Better a Filter today than an Injector tomorrow. Do maintenance and save your generator!

What are the engine filters for?

Why do the engine filters get dirty?

A generator should be subject to regular and precise maintenance, based on the hours of operation and on the time elapsed since the previous maintenance.

Formerly we talked about how it is essential not to mix up with the maintenance of a generating set and the replacement of the filters only.

fuel filter.JPG

When we mention the filters, we usually refer to the most common ones, in fact the generator’s engine, usually has four types of filters:

1. Oil Filter

2. Oil Filter

3. Air filter

4. Water filter, also called separator filter

To these you can also add pre-filters that are installed depending on the case and the different applications.

Why is it so important to replace engine filters?

This question has an intuitive answer, in fact it is known that in general maintaining something preserves its functionality, therefore the maintenance of an engine, including the replacement of all filtering elements, serves to keep the engine running and therefore the whole machine.

What some users, and also some technicians, still fail to accept, is the need to perform maintenance of the generator installed for emergency service which is also called "stand-by":  that type of generator that starts only in case of mains failure.

The commonplace is to check the number of total hours of operation and to assess based on whether the time has come to do maintenance.

The common place is to check the number of total hours of operation and to assess based on whether the time has come to do maintenance.

The generators in emergency service based on the hours totalled would not reach maintenance time even after 5 years, in fact it is rare to find an emergency generator that has worked for hundreds of hours!

Maintenance is to be carried out following the instructions of the manufacturer who usually prescribes the same at "n" hours of operation or every year, whichever comes first.

Why should the engine of a switched-off generator need to have filters and lubricating oil replaced?

To answer this question, let us take as an example the Human Body, an extraordinary machine that uses a very complex system of transporting oxygen and other vital elements to operate, such as "the blood".

When in carrying out its work, the Blood needs to be filtered, which is regularly  done by the "Kidneys".

Do the kidneys stop working when we sleep? No.

Is there any reason why we can voluntarily afford the luxury of "deactivating" our kidneys? Not even for a dream, we know that it would lead to death in a short time.

Even the engine, whether  it is diesel, petrol or gas, cannot work or simply be ready to run without a proper maintenance, even when it is "sleeping", that’s to say when it is off!

Even the best synthetic oil must be replaced. The engine lubricant does its job of adjusting the friction between the moving parts of the engine and preventing overheating of one or more parts. The functioning of the oil depends on its chemical properties, therefore an oil of a proven quality, which respects the specifications of the engine, can withstand maintenance intervals higher than a lower quality lubricant, but this does not drastically limit the need to replace it.

Paradoxically, a generator in an emergency network service may need to replace the engine oil in an equal way  or even greater than that of a generator set in "prime" operation, that is, it works continuously.

The emergency generators are (depending on the application) equipped with an engine preheater. Preheater is installed on the coolant circuit or under the oil sump. In both cases the preheating systems keep the engine warm and ready to start in any season.

Pre-heating operation is regulated by a thermostat that activates and deactivates the system based on the temperature reached. The result is a continuous, albeit slight, thermal excursion of the oil which, being preheated, manages to maintain the optimum viscosity in the event of start-up. All this has a price from a technical point of view, that is the need to replace the lubricant regularly so that it does not lose its lubricating properties.

What about the fuel filter?

It is advisable to make a brief reference to the type of fuel that we take into consideration in this article: Diesel fuel for motor vehicles.

Gas oil is basically born as a resultant fuel during oil refining, so we can say that diesel is a refining by-product. Obviously today diesel is a much cleaner fuel than before, but still maintains high concentrations of impurities. Often the fuel is contaminated by the water that creeps into the storage tanks.

How the water get inside the tanks is not a mystery, but even worse the situation is aggravated by the microorganisms that are formed in the contaminated fuel.

Given that many injection pumps are naturally lubricated by the fuel itself, the only way to avoid damage to the injection system is the Filters.

So the diesel filter serves to prevent water, solids, and other substances from entering the injection pump and reaching the injectors.

The average value of a diesel filter is € 30!

The average value of an injector or pump ... Well, forget it!

Better a filter today than an injector tomorrow.What are the engine filters for?

•  Why do the engine filters get dirty?

A generator should be subject to regular and precise maintenance, based on the hours of operation and on the time elapsed since the previous maintenance.

Formerly we talked about how it is essential not to mix up with the maintenance of a generating set and the replacement of the filters only.

When we mention the filters, we usually refer to the most common ones, in fact the generator’s engine, usually has four types of filters:

1. Oil Filter

2. Oil Filter

3. Air filter

4. Water filter, also called separator filter

To these you can also add pre-filters that are installed depending on the case and the different applications.

Why is it so important to replace engine filters?

This question has an intuitive answer, in fact it is known that in general maintaining something preserves its functionality, therefore the maintenance of an engine, including the replacement of all filtering elements, serves to keep the engine running and therefore the whole machine.

What some users, and also some technicians, still fail to accept, is the need to perform maintenance of the generator installed for emergency service which is also called "stand-by":  that type of generator that starts only in case of mains failure.

The commonplace is to check the number of total hours of operation and to assess based on whether the time has come to do maintenance.

The common place is to check the number of total hours of operation and to assess based on whether the time has come to do maintenance.

The generators in emergency service based on the hours totalled would not reach maintenance time even after 5 years, in fact it is rare to find an emergency generator that has worked for hundreds of hours!

Maintenance is to be carried out following the instructions of the manufacturer who usually prescribes the same at "n" hours of operation or every year, whichever comes first.

Why should the engine of a switched-off generator need to have filters and lubricating oil replaced?

To answer this question, let us take as an example the Human Body, an extraordinary machine that uses a very complex system of transporting oxygen and other vital elements to operate, such as "the blood".

When in carrying out its work, the Blood needs to be filtered, which is regularly  done by the "Kidneys".

Do the kidneys stop working when we sleep? No.

Is there any reason why we can voluntarily afford the luxury of "deactivating" our kidneys? Not even for a dream, we know that it would lead to death in a short time.

Even the engine, whether  it is diesel, petrol or gas, cannot work or simply be ready to run without a proper maintenance, even when it is "sleeping", that’s to say when it is off!

Even the best synthetic oil must be replaced. The engine lubricant does its job of adjusting the friction between the moving parts of the engine and preventing overheating of one or more parts. The functioning of the oil depends on its chemical properties, therefore an oil of a proven quality, which respects the specifications of the engine, can withstand maintenance intervals higher than a lower quality lubricant, but this does not drastically limit the need to replace it.

Paradoxically, a generator in an emergency network service may need to replace the engine oil in an equal way  or even greater than that of a generator set in "prime" operation, that is, it works continuously.

The emergency generators are (depending on the application) equipped with an engine preheater. Preheater is installed on the coolant circuit or under the oil sump. In both cases the preheating systems keep the engine warm and ready to start in any season.

Pre-heating operation is regulated by a thermostat that activates and deactivates the system based on the temperature reached. The result is a continuous, albeit slight, thermal excursion of the oil which, being preheated, manages to maintain the optimum viscosity in the event of start-up. All this has a price from a technical point of view, that is the need to replace the lubricant regularly so that it does not lose its lubricating properties.

filters engine.JPG

What about the fuel filter?

It is advisable to make a brief reference to the type of fuel that we take into consideration in this article: Diesel fuel for motor vehicles.

Gas oil is basically born as a resultant fuel during oil refining, so we can say that diesel is a refining by-product. Obviously today diesel is a much cleaner fuel than before, but still maintains high concentrations of impurities. Often the fuel is contaminated by the water that creeps into the storage tanks.

How the water get inside the tanks is not a mystery, but even worse the situation is aggravated by the microorganisms that are formed in the contaminated fuel.

Given that many injection pumps are naturally lubricated by the fuel itself, the only way to avoid damage to the injection system is the Filters.

So the diesel filter serves to prevent water, solids, and other substances from entering the injection pump and reaching the injectors.

The average value of a diesel filter is € 30!

The average value of an injector or pump ... Well, forget it!

Better a filter today than an injector tomorrow.

Power Generators Maintenance

The generator set maintenance.

The generator set maintenance is often mistakenly exchanged with the engine service. It is true that engine service is one of the main activities of diesel generator maintenance. However, it should be noted that oil and filters’ replacement do not always correspond to true maintenance this being just one of the many activities that are part of "maintenance".

Obviously, a non-specialized workshop will have the interest to pass off as a checked generator that actually, after 5000 hours, it never had  an insulation test.

Far be it for us to demonize the so much sold engine service but rather to highlight an indisputable fact, which is that a diesel generator maintenance is incomplete if you don’t know how to do it.

Do you have a trusted maintenance man? Is it the same maintenance technician who provides assistance on your electrical system, on the Boiler or even on your car? Don’t confuse friendship and business relationship.

Does your technician check the maintenance plan before working on your generator? At each hours intervals corresponds a type of maintenance, in particular for the generating sets in continuous operation. Have such intervals been respected.

If you’re an entrepreneur don’t forget that the generator is a machine and therefore it exposes your personnel at risks deriving from use. That’s why it is important that it should be always efficient and secure.

Should I do the service even if I didn’t use the generator?

If you do not use the generator, you still have to perform a maintenance every twelve months.

Like yoghurt, Lubricants and filter elements, as indicated by their respective manufacturers, have a deadline. even if you do not consume it at some point you have to throw it away

Lubricants loses its lubricating properties after a certain period of time and are unable to insure their performance.

If you are a skilled maintenance man, you should read the below article.


Diesel generating set maintenance: How to perform it by a professional

“We have a problem with the generator that does not start, Could you intervene please? It’s urgent”

“of course we can. Meanwhile, could I know when you have performed the last maintenance what were the last maintenance activities?”

“Maintenance has always been done but we don’t know when or exactly what was done. Oil and filters change for sure”

How many times have I had a similar dialogue with a new customer!

From now on, if you go on reading it means you are a professional, so perfectly aware of how a generator is composed and you know how insufficient the above mentioned activities and controls are, to confirm that the machine is functional and a full scale maintenance is performed. If instead you will stop here then you will continue to make a generic service engine convinced that this is the key element of the generator.

From where to start? From the start up.

Some may disagree on this first step but I like starting from the premise that the gens et must be working otherwise it is easy to run into the inconvenience of having performed all the maintenance and then to find out that due to an anomaly the generating set will not be in service.

Then after checking the coolant and engine oil levels, it is advisable to carry out a few minutes lasting commissioning ensuring that no anomalies are evident and there are no gross problems (e.g. engine fluid leaks). Only then the generator can be shut down  in "OFF" position (if necessary disconnect the starter batteries) to proceed with the maintenance.

The best use and maintenance manuals don’t mention it but the best maintenance starts with a start-up test such as to establish that before the maintenance the generator was fully functional.

It is not difficult to imagine how difficult it can be to prove to complete maintenance that a defect was present even before our intervention

It’s not a stretch to imagine how difficult it can be to prove after maintenance is complete that a defect was present before our intervention.

In the next article we will talk about the engine.

Case History: Power Generator under control with Remote Display.

If you have the right  solution and technology, monitoring a generating set remotely  is an easy task even without main.

Remote control of one or several devices is by now a common need for many applications although such need is not yet widespread when dealing with diesel generators.

One of our costumer who in Sweden deals with rental services for motion picture events decided to renew his generators fleet with our new Tesla generating sets taking advantage of  the remote management of  the generators.

His main problem consisted in not having  the direct command of the generator from his workstation and consequently he had to dedicate an assistant just to monitor the generating set constantly.

Who’s working on audio services absolutely  knows the problem: Supervising permanently the generator’s parameters and the fuel level is essential to avoid problems.  Providing events’ services means to ensure a flawless work and not getting the generator under control is for sure a big mistake.

There’s a common concern  in most remote control  systems and it consists in the reliability of the system , often subject  to local network’s configuration problems, Wi-Fi availability and even in the complexity of the system itself.

generatore remoto

Our solution has been accepted by the customer since it seemed to be the most reliable one. We equipped the switchboard with a remote display panel connected to the VEO main controller of the generating set with a serial Port RS485.

Why RS485? The simplicity of the RS485 serial transmission make it the fastest and most trustworthy data transmission system. Indeed, within 10 metres distance it can reach a speed of 35Mpbs and it is also a cheap and easy to install system.

display veo remoto

How does our remote display work?

It perfectly reproduces the generator’s display allowing to work as if the operator were in front of the generator. All the generator’s parameters and messages  are shown simultaneously on both displays.

Why not a Wireless system?

Actually, in a context such as that of a motion picture event or any other commercial event where hundreds of electrical wires are lying on the floor, managing the generating set  with a wireless system doesn’t make any sense. At least we believe it isn’t the best solution for our customer even if it would be more lucrative for us.

Watch the below Video...









The automatic generator is a generator equipped with a Diesel engine that can boot up in the absence of electricity,

We specify "Diesel engine" since a gasoline engine generator can be automatic but it is extremely unreliable because the petrol engine does not have the same startup speed after long stop periods as automatic generator sets usually do.

Automatic generator is a generator that operates according to the following logic:

1. It should identify grid failures or anomalies in network parameters

2. Start and control the Diesel

3. Pilot the contactors or one or more motorized switches / circuit breakers for the connection of the load

4. Detecting the Return of the Network in the Parameter Triggers

5. Switching for network / network connection  

6. Stop the Diesel

7. Return the position of the point 1 ready to repeat the cycle whenever it becomes necessary.

The above descrition is the ideal operating logic of a truly Automatic Generator.

The term "really" is used as a duty, since it tends to (even among industry operators) confuse an automatic generator set with a generating set that can "be started" through a clean contact  operated by a separate control panel .

If you want to explain in the second case the second case, it's like taking the startup contact behind the start button and taking it away to another electric board that can close and open the contact or press and release the button.

Obviously, the above-mentioned generator is by no means automatic and that it needs a further logic framework capable of detecting network presence and commanding the generator startup and shutdown. Apostrophate as an "automatic" generator like this is how to go to the fuel distributor and define an "automatic" petrol pump when you really are to refuel to the car. Reflective: It is a common definition but in fact it is an improper term.

A widespread current of thought argues that the management of the automation rendered separately, and therefore not directly into the generator, can give advantages in terms of system reliability since it can easily replace the ATS frame without having to intervene on the generator set.

Frankly, there are many, too many, reasons to reject this solution, which can only be considered valid in some particular cases. Let's just mention just a few of them:

First of all, it is evident that the situation is reversible, that on one hand it might be advantageous to be able to easily replace the ATS frame without having to intervene on the generator just as well as having a switching board without command logic is equally easy to replace without To intervene on the logic of management.

The first advantage of having a truly automatic generator, which has an automatic control panel directly on the generator, is that it has to do with a less control panel. Yes, because even a manual start-up generator set up for automatic starting with remote start contact will have its engine protection and generator management unit. It is clear that managing a single control unit is a "clean" job in most cases.

A) With an automatic control panel it is easy to have a clear situation of what is happening in the plant and on the generator. It also means that you have the generator and the network data available in one device. For example, we can interpret the load / load overload in the generator set behavior.

B) Sometimes the separate logic ATS is merely a line commutator, therefore it does not identify network problems such as low voltage, phase failure, single-phase voltage, etc.

Problems easily identified by the control panel mounted on board

A generator is automatic when it does it all alone. If it needs external intervention then it is not automatic.

Eventually it would be the "system" as a whole, to be automatic.

An automatic generator set is not just a control unit

If it was enough for a control and management control unit to make a generator automated it would be simpler, but that is not the case.

The automatic generator without a static charger would not be able to function properly because the battery of the accumulators would not be sufficiently charged to guarantee one or more start-up cycles.

The static charger is nothing more than a charger powered by the mains voltage to maintain battery charge even when the generator is switched off.

Preheating is another important element for an automatic generator that is often not taken seriously enough.

The start up of an emergency generator unit takes place by taking all electrical loads in one step. To make a comparison is as if in the mornings in the winter season we ignite the engine of our car and start immediately at full speed, perhaps by climbing.

The preheating, also called hot, is a heat source that is powered by mains voltage, keeps the water contained in the engine coolant, or the lubricating oil contained in the cup at a temperature. Both preheating types have the purpose of keeping the engine warm so that the engine can start up even with particularly low external temperatures and above all it can dispense the maximum power immediately without a pre-heating cycle without load.

That's why automates are born: not a manual generator too easily called automatic by vendors but a real automatic generator I no longer think about it.


Orefice Generators - Copyright 2017

Orefice Generators - Copyright 2017

When dimensioning the power of a generator, it is necessary to carefully evaluate the type of power to be supplied.

It's very comon that one has  a three-phase generator set and has to supply a single-phase load. How to proceed?

You must have heard that a three-phase generator of Power P = 3 kW can drive a single-phase power load of 1 kW because Pm = P / 3.

This condition is valid for all alternators with Star  windings connection and a voltage of 400 V, where to obtain the single-phase voltage of 230 V, we just power the load between a phase and the Star center.

“Single-phase loads powered by a three-phase generating set must be distributed in such a way that, at each phase, no more than the rated current of the generator is running.

Notice how we talk about power but also about current, because it is important to note that some loads at the time of insertion have a higher absorption, or higher currents. It goes without saying that an experienced technician can rely first on an experimental calculation, but then he must  measure the electrical loads distributed over the phases with the aid of a measuring instrument.

If you do not have a calibration tool, but you have a Generator branded Orefice with VEOTM control panel , you can easily monitor the absorption directly from the Display.

veo control panel

If you do not have a measuring instrument neither a generator  Orefice you will not be able to ascertain the correct distribution of loads between phases.

What if the loads are not properly distributed?

It may happen that the generator will go into distress and that the windings inside the alternator may overheat until they "burn" and interrupt.

To make a comparison, we imagine that electric load is a heavy shopping bag that we carry for hundreds and hundreds of meters with the same arm. We will reach our destination with a tired arm that is more subject to an injury. Dividing the load into two envelopes would not change the work to be done, and perhaps even fatigue, however it would be easier to carry the load to the target avoiding pain and risk.

Unbalanced loads are one of the major breakdown factors in an alternator and consequently in a generator set.

That's not all

An unbalanced load can damage the user connected to it, especially when it is a variable load. An electronic equipment user may not work properly.

That happens especially to Audio Services that hire or purchase a generator to which they then connect their panel without taking care to check how much current they are withdrawing from each phase.

Let's take an example to better explain what can happen:

· Generator with electric power Continuous power of 16 kW; Power factor 0,8; Rated voltage three-phase 400 V.

· Single-phase electrical load to be connected to a total of 8 kW divided as follows:

O Halogen lamps: 5 kW

O Other users with a transformer: 3 kW

Instinctlively the less experienced technician would feel free to connect all the halogen lamps under one stage and the remaining 3 kW under another phase. With this subdivision, considering a current of the halogen lamps that is at least 10 times the nominal current for an average time of 0,12 s, it will not only have problems with the lamps being switched on but will overload the generator for at least 0,12 s will not guarantee voltage and frequency values uitable for feeding the remaining 3 kW with the risk of causing damage to voltage values utside the limits.


During a sport event blackout is something extremely harmful and potentially dangerous.

Last May we were involved in supplying a 1600 kVA generator for a Qatar Stadium. 

For the occasion I was able to interface directly with FIFA to get information about the specificities required for the use of a generator during FIFA events.

FIFA introduces the subject in a very clear way:

"The delay or cancellation of an event due to the lack of electrical power is unacceptable."


A careful evaluation of the reliability of the main source is useful to the designer to determine capacity and size of all the  backup equipment.

We therefore wanted to analyze FIFA requirements and outline possible solutions, here is the result:

It is  FIFA   itself who  suggested this table.


Practical solutions for a Backup System in a stadium

The first solution represents the main power line disposed in two sources, a preferred and an alternate one (diagram a). 

Diagram A

Diagram A

In the second solution both utility services are in use and can optionally be configured as main and reserve with the help of manual or automatic switches. (Diagram b).

Diagram B

Diagram B

In the event of a Network failure, back-up power should start immediately, but there will be a time leg due to the seconds needed to start up the fuel and the load switching and takinf off, therefore, the back-up must consider and include some autonomy while the generator starts up since field lighting, which is typically a high-intensity discharge (HID), once it turns off, it requires several minutes to restart and the broadcasting will be interrupted.

This timing range is covered in a variety of ways, including special generators (rotating UPSs) and Uninterruptable Power supply system (UPS).

FIFA establishes a clear requirement of autonomy regarding the amount of back-up power that should have the capacity to operate for a minimum of three hours during an outage.

A stadium is considered a "high availability" system, or a system that is continuously operating for a long period of time.

The measure of the reliability of a system like that of a stadium can be expressed by referring to an ideal percentage of 100% of the use.

The maximum use percentage of the system called "five nines" or 99,99% means a downtime of only five minutes per year.

During a season, a stadium will definitely experience far more than five minutes of stop for repair and maintenance. However, idle times during an event must be zero for some equipment to avoid any interruption. This would require a power of absolute continuity.

Other equipment could tolerate the startup time of the generator (about ten seconds) and some parts of the stadium could tolerate even more.

Hence, the classification of load types should be considered to determine the amount of capacity and size of the redundant units of back-up generators and the UPS system.

Below we find what might be a breakdown of utilities according to a priority classification:

Security (generator available in 10 seconds)

- fire-fighting pump

- fire alarm and detection system

- smoke ventilation systems

- lifts dedicated to fire prevention

- eventual illumination of medical department

Event and Security (Generator UPS available in less than 60 seconds)

- indoor and outdoor lighting

- special departments (data / telecommunications)

- PBX telephony

- security and access monitoring

- giant video screens

Essential event (generator in less than 90 seconds)

- tables

- control room and control panel

- turnstile monitoring system

- police station

Critical event (UPS and generator, zero idle time)

- event lighting

- game control center

- police control illumination

Each section of the load would involve different transfer, wiring, and distribution systems, and the UPS may be static or rotating but will still require additional back-ups from the generator or a battery pack with at least four hours of autonomy.

 The most famous blackout in the world of sporting events

Surfing the web reveals news of singular and sudden blackouts  you can not imagine they can happen, each caused by different and more or less unpredictable incidents.


NEW ORLEANS During the second half of Sunday's Super Bowl, lights on half of the Superdome roof suddenly turned off. Internet connections in the press room stopped and lights off. After the sudden interruption, many of the 71.024 viewers began to murmur. The failure of about two minutes was one of the most incredible moments in the history of the Super Bowl.

In 2014 to SAN PAOLO A few minutes from the start of the World Cup's inaugural race between Brazil and Croatia, in the plant vip sector is lacking electricity and a generator is literally burning.  

In 2015 in Cagliari During a luxury friendly match between Cagliari and Real Zaragoza, after a few minutes the game is suspended because the two headlamps suddenly go out. The blackout continues until the end of the first half and the referee decides to resume the game even if the lighting is only partial.

In 2016 in Palermo During the match between Palermo and Torino, for a few minutes, due to a blackout, some of the lights at the Barbera Stadium have stopped working. Rosanero fans answered with irony trying to light up the cell phone and they chanted a chorus: "Zamparini pays the light" ...

In 2011 in Padua A high-ranking clash on the Euganean Stadium on the Calcio Serie B between the Padua and Turin captain, started to look fought and enjoyable, but that would have turned out to be a real mockery for the Grenades.

During the second race of the race, unusual extra-sporting events are taking place, affecting the game: the lights of the Euganean race continue to fail, with first partial and then total blackouts. Just during the first of these, partial, comes the grid of Ruopolo's advantage that mocks Coppola's grenade goalkeeper who complains of low visibility.

Turin appealed against Padua who there is a danger of a 25-30. 000 euro.

Former Padua and Turin, Roberto Muzzi declared: "Saturday was a great match as far as it was played. The black-out? These things happen, it can happen. "

In 2017 in the race between Flamengo and Vasco da Gama , A game destined to go to history as one of the most incredible. During the race a Blackout left the stadium lit up exclusively by the fans' smartphone lights on the stairs.

Surely in all above mentioned cases more than anyone has generated beyond the obvious economic losses a serious image damage that does not erase certain paying money.

How important is a generator in a stadium?

The answer to this question is "five nine".

Rather the right question would be how much the security and structure manager is willing to risk? What's more, how much is the Calcio team playing matches against you?

Anyone who is not willing to risk turns to a specialized company and is concerned about having the best backup system possible.

We can clearly say that in a structure such as the Juventus Stadium (Allianz Sadium) the precautions taken in this regard are definitely higher than those adopted at other stages where we are often relied on generators to use Shipyard, installed as if there was no tomorrow And perpetually in derogation to something.

It smiles like the unsuccessful generators with obsolete technology, which requires an operator to go directly to the generator to check fuel levels and operational status, while the rest of the world using up-to-date technology is sitting In a steering cabin to handle everything comfortably from a terminal.

It's as if to see if there's still fuel in the car you need to get out of the car and personally test the level in proximity through the charging cap!

Who knows how many times we hear the choir from the Curve

Or some of the hopeless romantic presidents like to see the stadium lit  by the fans' cell phones.

Power Generator installed at Alessandria Stadium (Italy).

Power Generator installed at Alessandria Stadium (Italy).


Generators, whether in emergency or in continuous operation, must necessarily be equipped with documents that permit their use, installation and identification.

What are the documents that should be provided, be it a new generator or a second-generation generator?

In EU countries having a generator without documents is like having a serious problem!

re, dell'alternatore e degli altri componenti del gruppo.

Installation, Operation, Maintenance Manual.

The manufacturer for each machine produced gives a user manual and maintenance that allows the use of the product in a correct and safe way.

The manual is that document (paper or digital) that each operator should read before installing or in any case before using the generator set.

Engine, Alternator, and Other Component Manuals.

It is not essential to have a specific manual for each generator component, except for specific cases. Generator generator usually provides the engine and alternator operating manual.

Manufacturers of diesel engine generators distinguish the manuals in different types, such as the user from the OEM or the workshop manual.

Single-functional and functional diagrams of the control panel.

Together with manuals and other documents, the connection diagram for power conductors and control and control logic (especially in the case of automatic generating sets) is always provided.

It is good practice in the case of purchasing a generator that is used, check that the components and electrical connections are faithfully in line with the manufacturer's drawings. This is to safeguard the unhealthy purchase of tamper-evident machines and therefore no longer in compliance.

Assembly and installation drawings.

The obligation to supply designs of the generating set is defined in the contractual terms. An assembly diagram or a definite design is also known as "as build".

Documentation of any tests carried out.

A capitalized "C" builder performs functional testing and is responsible for all generating sets produced while others perform sample testing to limit production costs that inevitably affect the cost of the product.

Factory testing is a guarantee for the buyer because it minimizes the possibility of failure at commissioning.

In an optimum and real-time quality management system, testing allows any non-compliance to be handled before it can be transmitted to the final customer.

There is no obligation to provide the document certifying the generator's working test, which in any case is a part document.

It is important to distinguish the Test Report from the Test Certificate. The first can be provided free of charge upon request, while for the second one may be provided for a fee.

List of recommended replacement parts for commissioning.

It is necessary to dispose of a myth concerning the parts needed for commissioning: in 90% of cases there are no "necessary" parts for commissioning a generator. In the remaining 10%, these are consumable or specific parts for a particular application.

Warranty certificate.

A generator has a manufacturer's minimum guarantee of 12 months. The warranty certificate is required for the activation of the warranty, since once it is compiled and returned by PEC or recommended, it is a certain date of activation of the guarantee and allows the manufacturer to activate the guarantees of the various components.

Activating late warranty may be a problem, as most manufacturers set a maximum time limit between the delivery of the generator and its activation.

Certificate of conformity.

The purpose of the certificate of conformity is to ensure the free movement of goods within the European Union.

The document is always mandatory, and it is important to clarify some points:

A) Must be supplied in conjunction with the generator set. He must accompany the generator throughout his life.

(B) If the generator is produced outside the EU, the certificate of conformity must be issued by a Community entity, so if you decide to buy a product made in China (for example) then it is good to make sure that the importer has provided To issue the certificate.

(C) The importer entering the Community market shall be solely responsible for the marking and the relevant document.

By doing so, we see the data that must contain a certificate of conformity.

The EC declaration of conformity must contain the following elements:

- the name and address of the manufacturer or his authorized representative established within the Community;

- the name and address of the person holding the technical documentation;

- description of the equipment;

- the conformity assessment procedure followed and, where applicable, the name and address of the notified body which carried it out;

- sound power level guaranteed for the equipment;

- referral to this directive;

- declaration of conformity with the requirements of this directive;

- where applicable, the declaration of conformity and the other community directives applied;

- the place and date of the declaration;

- details of the person empowered to sign the legally binding declaration for the manufacturer or his authorized representative established within the Community.


The generator TF80  is operating in Uganda near Lake Victoria.

It is a Generator successfully integrated into a modern power plant operating in Island mode with the  purpose of supporting the storage system connected to a photovoltaic park with more than 800 panels.

The plant is equipped with an "Energy Management System". An advanced energy management system between the various components, and a "Battery Management System", that is, an intelligent battery management system.  

The plant provides electricity to over 500 domestic and commercial users, enabling them to have a continuous service of lighting and power supply to various electrical devices for domestic and commercial purposes, such as mills and ice machines,  supporting therefore the fragile local economy based almost exclusively on fishing. The use of electricity is handled via a cellular prepaid system, and is monitored through individual smart meters connected to each other as well as  remotely.

I work with a Company that has already purchased the is reassuring to know that Orefice support is very responsive...

How does this generation plant act in Island mode operation and what is the generator for?

This plant bears the distinction of being placed in a context where the power grid does not exist, so all the produced energy is consumed by the users or stored in a Vanadium accumulator battery.

The generator unit comes into operation only when maintenance is performed on the storage and / or the production part, but also in case of excessive power demand for the plant itself.

Are there any other similar power plants?

In the past we have provided generators for similar applications with different powers, starting from 2 kW with generator 24 VDC or 48 VDC, all automated to start the generator automatically when the charge of the batteries is low.

All these applications, regardless of power, have in common pursuit of energy continuity, which is always the basis of our solutions.


Rain comes. If you do not have a generator you are in danger.

In Italy, in September, October and November every year is the same story: The rain expected for an entire season falls in a few hours. The consequences can be devastating and vary depending on how much you are prepared for the extreme event.

How frustrating it is when you lose valuable goods and sometimes a lifetime of memories.

Being prepared for such an event means to be equipped with systems and facilities capable of preventing the accumulation of rainwater. A common example is water lift pumps, usually placed in basements and underground rooms, with the purpose of preventing flooding from rainwater or worse, of sewage seepage infiltrations. Being mainly submerged pumps, their functionning is closely related to the presence of electricity from the grid or from auxiliary sources such as generating sets.

Owning an emergency drainage system for rainwater and not having a generator set is as useless as preparing for a long and important car trip without taking care to fill the fuel before leaving. What a feeling will it be when everything does not work? Anger and frustration will be double.

What is the relevance of a flood or flood and the lack of electricity? It is simple: when there are atmospheric events that interest entire cities or regions, it concern all the infrastructures, including the electrical ones. In exceptional cases it may be the same network operator to establish the disconnection of an entire area from the rest of the network.

The moral is that without electricity electric pumps will not work and you are in danger.

Recently a Hurricane has devastated the Caribbean Sea and then crashed against Miami, USA, leaving millions of people in the dark for many days.

Only those with proper generating sets and high quality fuel loading facilities could face the emergency. By looking at the Social Network images of those who "thanked" their generating sets for the great work done during the emergency, I noticed that everyone set up images of professional generators. In other words, the most striking success stories were possible with really good generators and not the ones that you can get for 149,00 Euros at the mall.

In the picture below, just to give an idea of he difference, you can see  on the left a true generator suitable for emergency use while on the right a toy  where nothing is funny about it.

generatore vero e giocattolo

Beware, they both have the same power !!

In one of the next articles, we will explore the issue of the best generating set for housing, thus we will explain the technical characteristics of a generator set for the safety of your loved ones and your properties.

Meanwhile, let's try to understand schematically the difference between a generator suitable for operation in emergency conditions and one not suitable for this purpose.

condizioni scelta generatore

Dimensioning the generator set in accordance with the electric pump or vice versa?

Anything to do with sizing would deserve a separate article, however, a guideline can be outlined to approximately define a power.

First, it is useful to determine which loads to supply, thus, to decide whether to connect the generator to the electric pump or to the entire building including the rainwater lift system.

Choosing to supply an entire building will determine the nature of the loads, the priority and the timing.

Nature of loads : Single-phase or three-phase electrical loads.

Priority: A priority electrical load is such when it comes to an important device. Example: A refrigerator, video surveillance, water drainage.

 Timing  : Not all electrical loads work at the same time, so the required electrical power may not match the sum of all detected loads.

Regarding power, there are no great deals unless the attention to   not dimension the generator at 100% of the load. (A 5 kW electric load should not be powered with a 5 kW generator.

"Sizing" is not just the experimental calculation of the power involved, but it is also the choice of fuel tank capacity that affects the amount of hours the generator can remain in operation.

Placement of the generator:

you need to find the best position of the generator set. If you plan to mount your home-based generator in the basement, or hidden in the sight so that noise cannot disturb, you're starting off on the wrong foot.

If you do not want to hear the noise during the generator motion, you have to install a soundproofing unit (see previous article). Also, choose a generator that is aesthetically up to the environment in which it will be positioned.

Get advice from a professional about where and how to place your home-saving generator.

You'll do a safe and  productive job and you'llthank yourself for being far-sighted.



"We stayed in this residence a few days ago for new year's day, a bleckout from 9.30pm up to 04.00AM without any informations from the Hotel Stuff. Obviously, no way about a refound...”

[The Hotel response]

"Dear. Mr Matteo, we are sorry for the discomfort caused by the lack of electricity during the hours you mentioned but, as communicated to all customers, the problem was caused by a failure in the electric cabin of Enel and our staff Maintenance, always present until restoration, was not authorized to intervene. "

If you don't want to justify yourself to your customersas a kid with your customers for something you don't even have to be blamed for, you absolutely should  read this article ...

In the modern era, where even the most complex operation is carried out using a smartphone, telling a customer that the fault comes from your network operator sounds ridiculous.

How  would you like it if the restaurant owner told you that your Carbonara Spaghetti will never come to your table because "those of the gas" did not bring a loaded gas cylinder?

You can not bounce on the Customer a problem that is exclusively yours.

Emergency Generator at the Hotel: Why you shouldn't  underestimate it.

Have you ever tried to keep your eyes closed for a few minutes? Just to test your other senses and maybe orient yourself in a room or a premise. Some of us  wake up at night, get out of bed and drink a glass of water without opening the eyes not even for a minute.

My grandfather, though he missed sight as a child, used to remember by heart most of the electrical wires of an electric motor, and was even able to tell others how to connect. Even today, talking to him, I wonder how he did it! I hardly remember what I ate yesterday.

One thing is for sure, though: staying in the dark without seeing anything is difficult. Every operation becomes complicated and you feel a very intense sense of insecurity , so that reopening the eyes, makes you feel like a great relief.

Now, however, we try to make the situation more complicated by the fact that more people inside the same room close their eyes and have to get inside it without hurting themselves.

I think it's definitely complicated, do not you find it?

If you turned off the light, were you? In this case you have no reasons for staresereno.

Should any of those who are in the dark get harmed? No one would want to be in your place.

Maybe you will not believe it but this is what can happen in a hotel when electricity is lost and everything goes out: lights, elevators, hoists, computers, telephone switchboards, video surveillance, home automation, etc etc A large number of people (including you) find themselves closed-minded to have to move hoping they will not do harm and above all not hurt someone.

Maybe you're thinking I'm just pulling water out of my mill, and here you live blackouts and emergency generators during blackout, but you're wrong.

In fact, the solution to the situation I have imagined before is not to have an Emergency Generator in the Hotel, but something more: " Possessing an emergency generator that is really efficient ".

Between having an emergency generator and having one working there is a big difference, like that between launching an airplane with a parachute or throwing a rucksack.

Most of the hotels with a couple of stars and a quality-oriented property feature an emergency generator, but only 3 accommodation on 10 has one that actually works.

Why? It's simple: they do not do the proper maintenance!

When a computer does not work, or when an air conditioner is failing, the facilities quickly resolve the problem, and when it comes to emergency generator sets it seems there is always time available.

If you are a maintainer and you are wiping your nose, I can assure you that you are misunderstood what I have written. I know you are maintenance to the generator, but we both know that you sometimes have some sometimes structural and / or temporal limits for which you certainly have no fault. (You probably often find yourself doing more than you would have to do).

We can say, if I were a top-of-the-line generator, the generator would be the most efficient machine in the facility and it would not be in the least economic and image loss.

I remember the matches of Soccer where the goalkeeper who missed the last minute and missed in turn came to the door. It happens then that at the end of the game there is always the "phenomenon" that pulls the sums with other comrades on how many goals the team lost my fault while I was in the door.

Now I say, but in my opinion if I was a "good goalkeeper", would I ever play soccer with you ?!

That is why it must be objective: The regular maintainer, though good and prepared, can make some nice parade, but to save a penalty it will take a real Goalkeeper!

 Security: Protect yourself

Bullets, burnt, crushed, suffocated, mutilated: Generating sets may die.

Being aware of those who are at risk while starting a generating set could make the difference between a live and a deadman maintainer.

Speaking of security at the hotel or in any accommodation facility, restaurant, bar, etc, we refer mainly to two figures, that of the client is that of the employee in the structure.

Both figures must be protected in the same way but with different systems and instruments since it is clear that the level of information you can give to the customer is not comparable to what you have to give to your staff.

In order to protect you, you have to protect it, so in practice you have to give evidence of how you have provided specific training on the generation of the generator and how this has been maintained efficiently through regular maintenance activities.

Costs: how to handle them

Specific strategies can be adopted to optimize the costs of managing a generator.

The first thing to avoid is that you do not handle the maintenance regularly. Statistically, a maintenance-free generator does not work right at the moment it has to work.

An intelligent way of managing costs is also to plan the most important maintenance interventions during low attendance periods, allowing scheduled rematches and functional tests, avoiding having to require night or week breaks at higher rates.

Safely manage a generator failure at the Hotel

For your safety and that of your collaborators, I ask you to avoid improvised and precarious solutions that may turn away from you. It's better a blackout than a serious accident.

As soon as you notice a blackout that is not readily contained by the emergency generator, you can proceed by following these three simple steps:

1. Find out the magnitude of the blackout. You have to determine whether this is a fault in your facility or a failure affecting a wider area served by the electric operator.

2. Make sure there are no Guests inside any elevators, and then put them out of service.

3. Only after you have made the previous steps you can collect the ignition information and contact the service center. When contacting the service center, keep the generator, engine and alternator nameplate data available.

If I read this article is a Hotel Manager or a maintainer, I can prophesize with certainty that in the event of blackout and failure of the generator, both will rush in front of the generator to try to figure out what is happening.

I know very well what happens in these cases, so I thought about giving you a gift: "A cover for the main breakdowns of the generator". It is a poster we provide to all Hotels that enter into a maintenance contract with us. It is very useful in case of failure because it allows you to understand how to operate and contact us aware of what is the information we need.

Our "hotels" usually expose them outside the technical premises, or they keep a copy in the office at hand. Often they have solved many problems autonomously without cost of intervention.


How much  a used generator is worth? What are the most important checks to do? Find out how to choose a  used generator   even if you do not have special skills in the mechanical or electrical sector!

(Video at the bottom of the page)

If to buy a generator we have to avoid only 6 mistakes  ( so to speak), when  buying a used generator, the situation gets complicated and it is crucial to be able to select a generator without ending up on something that can reveal a bad purchase.

The main concern is not the fact that someone before us used the generator, but rather is it the fact of not knowing if he used it with scrupulous and careful attention.

The ideal thing is to get along with an expert, a professional who knows what to look at and can distinguish a deal from a mass of problems

It's natural though that if you're reading this article you probably do not want or cannot get a hand lended from anyone, so let's go straight away with the information you need to not fall into a wrong choice.

Identifying the Generating Set: Is It Really It? Has it been tampered with?

A key step before proceeding with any test is to identify the generator unit by verifying that the data on the plate conforms to the documents submitted by the vendor.

Verify the identity of the generator, verify that no tampering has been occurred.

We are talking about changes that compromise its operation. Let's take some examples:

The emergency stop was inhibited; The shutdown system has been changed; the EC caps have been removed from the engine; the switch has been replaced with one having different characteristics, the operating logic has been changed, changes have been made to the chassis or bonnet, etc etc.

Without documents it's never a deal.

We will often make similarities with cars. An Unlocked Generator Set and like a car without a circulation card.

Some people make the mistake of thinking that a generator can later be equipped with the documents needed for its use, but this can never be taken for granted.                      

Issuing documents, especially when it comes to products from other manufacturers, is an expensive operation that many  tend to underestimate.                       

Actually issuing documents for a machine we did not design and we did not build is a great responsibility towards the user and to those who designed i considering the main risks and residual risks.                      

It is crucial when you look at a used generator  to ask the owner to show you the generator's documents.                       

These documents are the certificate of conformity, user manual, maintenance manual. Sometimes the user manual and the maintenance manual are in the same brochure. If you want to deepen the topic, we have dealt with this topic in another article dedicated to generic set documents.                     

Drawings, technical sheets, and other material are useful and very important elements but are not indispensable, and above all they are not mandatory for doing business with a generator set.

Reissuing the documents due to the loss of the originals may be required through the intervention of the original manufacturer.                       

Reconfirming the compliance of a generating set binds the certifier to produce a complete technical file and a residual risk analysis.                       

In addition to being compliant with the regulations in force, the documents must comply with the identification plate on the generator set. The plate must bear the CE marking, the power of the generator, the generator model, reference standard, and other  technical data to identify the machine and its operation.                       

A generator set without documents could not be sold, and in any case could not be installed and used.                       

A generator with a certificate of conformity can be installed, but cannot be used if the user manual  is not present on site.                       

The recertification of a generating set provides for the availability of documents useful for issuing a new certificate. They are the documents relating to the main components of the generator, for example the diesel or gasoline engine, the alternator and other components of the electric board.                       

Hours to work, year of production, but not only.

Working hours are important but must be evaluated taking into account the context in which they worked.

Let's take an example to understand the concept: Would you prefer a used car that has 100.000 km mostly on the highway or one that has  run 100.000 km on a mixed path?

Is it better having a generator that worked a few meters from the sea , a generator that worked in a sand quarry, or a generator that was in emergency service at the mall? Salt, sand, or the quietness of a technical room in the underground of a building?

In the case of the generator, we must first evaluate whether the operating hours have been totalled in a continuous or emergency mode, then try to understand in which environment it has worked.

The engine, this is what you must never neglect.

Take a look at the engine .

There should not be excuting fluids. Check the belt that is usually well visible.


During a cold start a black smoke or a white smoke may be normal.

Black smoke: In the case of  black smoke  during operation, there is probably an excessive consumption of oil , from the dirty oil filter, or the presence of exhausted engine oil.

White Smoke : The emission of white smoke during operation requires deeper checks because it can mean a lot of things. It could be caused by a low amount of coolant, by the presence of water in the diesel, an injection delay, a cracked piston, the head gasket, etc.

Please note that during operation at load, the smoke increases considerably.



Check the status of the anti-vibration pads: with the engine off and cold push the coupled alternator motor to one side. The engine must move and return to position without residual oscillations.

Do not neglect this detail, it is a matter that only experts control. A generator that is proposed as "equal to the new" will have all the kit of anti-vibration in excellent condition.


Cooling Radiator

Open the coolant cap: there must be no oily residue,  which indicates a possible fall in the head seal.

You could repeat the control before starting and after the test run. Be careful during these checks, the liquid temperature is burning.


Noise Frequency and Voltage under load

Consider when the load is switched on, if the motor reacts promptly by returningvoltage and frequency to nominal ones.

Quality and Pressure of Lubricating Oil.

When the engine is cold, check the oil level, and with a cloth score if there is a possible presence of solid residues, a symptom of engine wear.

When th engine is hot, open the oil filler cap, there may be a natural outbreak of hot vapors but there must not be an oil spill.

Connections and wiring

Check that the system is in order and that there are no traces of burnt or rigid or deteriorated conductors.

Security systems

The generator must automatically switch off for low oil pressure, high coolant temperature.

Try also the emergency stop button. (Required). Shutting down should take place within seconds.


Operating test .

If you are purchasing an automatic generator, simulate the lack of network by selecting "Automatic" mode from the control panel. The generator must start the engine in 5 few seconds.

It may not be enough to start the engine and check that the voltage is at the nominal level. The best test is the load, at least 50% of the load that the generator can withstand. A charge test could be paid as it involves a technician and there is a natural fuel consumption.

The Alternator, fundamental but never verified.                  

The alternator is one of the most neglected components in the generator, although it is also one of the most expensive after the first engine.                       

More than half the problems experienced by a user who has a used generator is to find surprises on the alternator.                     

In fact, on the 90% of the generating sets only engine maintenance is often performed and often not complete, reducing the replacement of filters and lubricating oils.                        

A regularly maintained and revised alternator by a qualified and experienced personnel has relatively high life expectancy.                       

One of the reasons why the alternator is never verified by the user who intends to buy a generator set is the general lack of expertise in understanding the aspects to be verified in the alternator                      

It is important not to ignore the fact that the alternator is made up of rotating parts that are subject to vibration and mechanical stress which over time can create wear and then fail to adequately repair them.                       

Few people know that the mono-support alternator, equipped with a single headset bearing, has a well defined maintenance plan that provides for replacing or lubricating the stand regularly.

The control panel.

The control panel is essentially an electronic component. Make sure it is the original one assembled by the manufacturer of the generator, if it's not the case, ask for information on the kind of intervention performed.

Remember that if the control panel is replaced on a generator set without the necessary adjustments, the operating hours start from zero.


Clear signals but almost (all) ignore it.

It's not all. There are signs that only a watchful eye can notice. In fact all that we have explained in this article is 50% of what you should know, a share of all respect that will allow you to avoid throwing away your money.

From whom to buy a generator set used ?

Used generating sets can be found by private vendors who have ceased their activity, from specialized dealers and dealers.

The suggestion is always to turn to a builder first because he will not take the risk to put into service used machines  that could bother him and make him bad publicity.

Resellers and small craftsmen are an unknown, in our region, for example, there are companies that retrieve scrap of years 80 and restructure without a criterion and without producing really valid documents.

Manufacturers or their dealers, on the other hand, often take over generating units that have not accumulated a large number of hours and sell them at competitive prices.

Used yes

Watch the Video with Tips to Purchase a Used Generator That Works. What to check, what to ask, what are the most important things and all you need to be sure that the use you've identified is actually what you need.

Watch the video with tips for buying a used generator that works. What to check, what to ask, what are the most important things and everything you need to make sure that the used one you have identified is actually the one that is right for you.


Get your money. Hand it to the generator seller, the "Generators Monger", and your new generator will be delivered to you.

Easy, isn't it?

For some people, buying a generator set was such an experience, so simple before but so hard afterwards, when you find that you bought the wrong one.

I could assure you that by buying a Generator Orefice Generators Bla bla bla bla bla bla bla bla bla ..., Customer orientation, bla bla bla, quality, etc etc, but I want to do something more to be out of the 6 mistakes that you should not Absolutely do when you buy a generator set. I would like to tell you that you are on the other side of the bench.

Whoever purchases a generator can be a final user, the one who will actually use the product, or a reseller who may install it or put it into service. For both figures we have important information, so do not give up and come to the end of the article.

If you really want to buy a piece of junk, well, at least you will do it fully aware and informed.

1.  You don't know why you need to buy a generator.

Trivial but so important.

You can not buy a generator without knowing what kind of application you intend to run. Before contacting a manufacturer or installer / retailer, get yourself together and collect these data:

· Do you want a generator that starts when the power supply is missing or do you want to start it manually?

· How many hours a day will you use the generator?

· What kind of equipment would you like to supply with the generator?

· Do you know the power and voltage of the equipment to connect?

To be clear,  even in the absence of the information above, many will be able to formulate a bid, but it will be an economic proposal and not the "solution." If you ask for an offer without providing these details, it will be like deciding on the place to go for a holiday by spinning a globe and picking a point: you have a huge chance to end up in the Pacific Ocean.

2. Thinking the only difference is the power.

The first mistake, which is also the most widespread, is to believe that generators are all equal and that the only difference lies in their power.

Well first  you have to completely reset this conviction which will lead you at best to spend more money, and at worse to buy something you do not need and you will not be able to use.

If I offer you a trip asking you to choose whether to travel driving a Lamborghini Aventador or on a dromedary hump, what would you choose?

Have you chosen Lamborghini?

Can I make you change idea if I tell you that the proposed trip must cross a desert of sand dunes? I  think so! Although you are probably not an expert on Lamborghini and Dromedaries, you will surely reevaluate your choice because you understand that there are important differences in the result, though both are very different means of transport. You also know that the most suitable product is related to nothing else but your need.


When choosing a generator for you or your customers, do not evaluate only the power.

If the generator is for you or your company, consider at least these three elements:

· Maintenance intervals and related costs.

· The presence of all the equipment that allows it to operate.

· The brand of the engine and the presence of a brand distributor in your country.

If the generator is for your customer, you may think that the previous points do not concern you, but always remember that the customer is yours! Whatever you propose, any product you install will remain your Customer, maybe you will not say "thank you" when you have provided a working product, but be sure it will make a nice registered letter when the product you provided will not be what you expected or Even will not conform to the specifications.

So pay close attention to what you bring to your Clients :

· Consider the application and the power you need.

· Consider installation costs carefully.

· Please note that you may have to provide some kind of assistance during the warranty period.

3. Look but don't read.

We have to realize that 90% of people who want to buy a generator (this is not only for generators) do not know how to read a quote, especially when it contains a large amount of technical and operating specifications. With this we are not insinuating that 90% of people do not understand anything about generating sets, but reading an offer is often  misunderstood, and the part where equipements are mentioned is neglected

Magic tricks are not a rare thing, it's a widespread  vice, with offers for supplying generator sets without fuel tank, without main switch, no silencers, no starter batteries, no liquids Of the first plant, just to name a few.

There is nothing wrong with proposing a generator without one or more of the above elements, provided that this difference is technically considered first and then economically.

4. Go buy tomatoes back with the Onions

"The engineer told me that I need a 10 kW generator in continuous duty, three-phase with electronic xxxx engine 1500 rpm".

Then it happens that you meet the pitchman that does not distinguish a diesel engine from a gasoline engine and come home with a 10 kW single-phase generator withengine at 3000 rpm .

It is not an extreme example, it is a real case, a common story among many who are lost in the purchase of a generator, for inexperience, for the belief of making a deal, lack of competence, and so on and so forth .

Have you ever been to go shopping and buy onions just because you did not find the tomatoes?

I really do not think so! So why buying an "inappropriate" generator just because you did not find the generator you were looking for?

I propose you a logical patterns to follow in order to better evaluate your choice.

Gasoline engine generator - Only for "manual" applications, never for automatic applications.

Generator with Diesel Engine at 3000 rpm - Only for non-continuous applications, max 3 / 4 hours per day or with a break of at least 2 hours between each work cycle.

Generator with Diesel engine at 1500 rpm - All applications with continuous and intensive use.

Generator set with Diesel engine electronically controlled - For applications where you have sensitive devices.

5. Buy a "base" product  convinced that you can modify it.

The unsound idea usually arises for budget reasons when you can not afford anything but want it the same, so invent a project that allows you first to buy a basic product and then turn  into a McGiver trying to modify the generator.

I have to disappoint you: in the vast majority of cases you can not do it. You can not modify an EC marking machine without proceeding according to the standards.

Do you want to buy a generator with manual start and then turn it into automatic? You will spend more and you will have to certify it.

Would you like to buy a generic open cabinet without cabin and then build a "home" to fit it? You will spend more, also the "home" will be compared to a technical room, so it will have to comply with some specific features.

The advice is to make a measured but correct investment, buying everything you need and all the necessary options directly mounted at the factory.

6. I will never use it

"I will never use it." We often hear this phrase from many Customers. They are convinced that they will install the generator and that this will never come into operation, because "so much current is never missing".

You know the biker who did not put the Helmet because "It's okay, I don't fall that easy

This generator theory that will never come into operation has been carried on by some manufacturers who wanted to market products with low-cost Chinese engines and alternators. Commercially, it perhaps, makes sense, but to technically justify such a stupid choice they invented the story of the generator that will never turn on.

If you are convinced that the generator will never start, then do not buy it!

Here is the full video where we talk about the mistakes to avoid when purchasing a generator.

If you like Video, subscribe to our Youtube channel to stay up to date on all of the upcoming videos.


The difference between a Generator with engine 3000rpm and 1500rpm

What's the difference between a generator set 3000 rpm and 1500 rpm?

A generating set per definition is a combination of an internal combustion engine and electric generator.

The most common engines are those Diesel and Petrol engines with 1500 rpm or 3000 rpm, means revolutions per minute. (The engine speed can also be lower than 1500).

So what is the difference between a  generator 3000 rpm and 1500 rpm one?

Technically we have already answered: one engine in one minute executes 3000 rotations, while the other in the same minute runs 1500, or half. It means, in other words, that if a speedometer measure the number of turns to the shaft of one and the other, we will get either 2 revolutions and 3 revs respectively.

This difference leads to obvious Consequences that should be known when buying and while using a generator:

Life Expectancy

An engine with 3000 rpm has a lower wait than the engine 1500 rpm. This is due to the strain difference to which it is subjected. Think of a car traveling at 80 km / h in the third gear and a car traveling at 80 km / h in fifth gear, both reaching the same speed but with a different mechanical stress.

If we want to give numbers, we can say that a generator set with diesel engine 3000 rpm reached 2500 hours of operation may need a partial or total review, while for a diesel engine 1500 rpm this may be necessary after The 10.000 hours of operation. (Indicative values).

Operating limits

Some say 3 hours, more 4 hours, or 6 hours of continuous operation.

A 3000 rev / min engine has a limit on running time, usually after a few hours of operation it would turn off to allow it to cool down and check the levels. This does not mean that it is forbidden to use it h24, but that continuous use is not appropriate. A high number of laps, for a prolonged time, is not ideal for a diesel engine.

Weight and Dimensions

The engine at 3000 rpm with equal power has smaller dimensions and weight than the 1500 rpm since it has different technical characteristics to reach the rated power. Usually these are air-cooled mono and two-cylinder engines.


Running Costs

The cost of the 3000rpm engine is lower and, consequently the generator’s cost too, and even the running cost is different: usually an engine working under stress tends to accumulate over time in number of failures and maintenance higher than the average.

The noise

The noise of a motor generator at 3000 rpm is usually higher, and even when it has an acoustic pressure similar to that of its half brother with engine 1500 rpm, the sound frequency is more annoying in the case of the motor 3000 rpm.

Taking these aspect into consideration you will have a better idea to select and use Your generator.

When you SHOULDN'T buy a generating set...

When you SHOULDN'T buy a generating set

When estimating "how many" … is important.

This is not a title made to draw your attention. In this article I intend to explain you from my perspective what are the cases in which you absolutely shouldn’t buy a generating even if this could work against my own interests.

The difference between an amateur and a professional is that the first will tell you anything to sell, the latter will tell you the truth even when it is inconvenient and could postpone the sale or even lose it.

If, within a scale of values, having a generating set features in a low position you probably found the first reason to not buy a diesel generator: You don’t need it!

Trivial as it may seem, it’s actually through such evaluation that the other reasons of why you don’t have to buy a generating set could be argued, first and foremost : possessing a toll you don’t need it.

Estimating how many … you will use it

There is one customer’s claim that I often face and it is linked to "how many time” will the customer use a generator? There is a spread like wildfire conviction that if you intend to use a generating set few times a year or not even once, then you can definitely buy a well painted metal box as a generator but it will be a lame machine. This way of reasoning is the exact opposite of what we do every day which is to buy valuable goods perfectly aware that once we will need them, they would be useful and appropriate.

Let’s make a simple example: If you are looking to buy a new computer, what will you do? I don’t think that you will walk into an electronic store and just ask for a computer!!

According your needs, you will probably start to look for the model that might be suitable for you keeping a very close eye on the features as well as on your investment, weighing the options, the performance, the warranty and the reviews . If you have a little bit of common sense you will not consider buying a computer (which is not nay one item) on the basis of how many times you will use it. Especially because in many cases, you don’t know .

The reasoning on how many time is more frequent in the case when you are under the obligation to have a generating set for emergency . in this case you can save money by buying the diesel generator that costs less so long as it complies with the requested characteristics . this is exactly the sort of thing that we can find in the public works where there’s all kinds of weird stuff, often on the fringes of legality.

Actually, I can guarantee you that in all the cases where you’re required to have an emergency generating set, it will be of real use and it’s in those moments that you should be sure to have chosen the best one.

Furthermore, the fact that it won’t be you who will use it if you think about it, is a double-edged sword.

In the last 10 years in Italy and elsewhere, are sold products prepared Italian with low quality components and sold for all standby applications where (you do not understand the basis of what criteria) it was determined that the generator will start once a year or maybe never.

The immoral reasoning from some houses and explained in no uncertain terms is this:The unethical argument directed and bluntly put by some manufacturers is the following:

"“Dear valued customer, considering you want to save money and you would probably use the generator once a year, I intend to offer you the perfect one that suits you. It’s just that it sucks and it’s got an engine that I’m not sure if it works properly, so I will give you the warranty of 250 hours running per year!”  ".

So in one fell swoop, he told you that:

1. To save money you have to give up something. (perhaps you didn’t even raised the budget issue but he anticipated it

2.  You don’t need a diesel generator

3.  I am selling you something that without any normal warranty

If we try to put the same reasoning into another field scale, the insurance sector for instance, they would sell you a policy that you won’t need and without the covers that you are expecting and with a relief that you won’t forget for the rest of your life.

This sale method, studied to make up numbers, found a breeding ground in many firms which provide turnkey plants installations in which, among other things, they must install a generating set for emergency application and in that case, the aim is to keep costs down playing on the customer’s lack of competence in the field of diesel generators.

I don’t want to say that quality lies only in the engines and alternators’ big brands, however, I’ve seen generators that rusted as soon as they were put into service and also generators that showed liquids leakage or power outages…

Last November, a retailer/installer told us his bad experience with a made in Europe diesel generator which at the moment of first starting up it dragged the alternator ripping it from the frame and spinning it on itself.  The result was:

• A lame move towards the customer.

• He was forced to replace the generator at his own expenses.

• He has been the subject to of a negative publicity in his sector.


The question is, what are the other cases where you shouldn’t buy a diesel generator?

1) If you think you will use the generator only for a few time, don’t buy it!

You could light romantic candles during the black out and if this black out is extended you could rent a diesel generator.

2) If you think that you will use the generator for few hours during the year but the security of people is linked to its good functioning so … buy a true one!

Is the process of your company based on electrical energy? Does people safety depend on a diesel generator for emergency application in a certain way? In that case, for which reason you should save few euros to have something that gives you less performances?

Everybody can spend less giving up something!

I saw application where to the diesel generator  functioning people safety is connected and where the generator is equipped with engine and alternator that even the manufacturers are ashamed to brand it, yet it is there running in an important facility.

What do you think of a second hand diesel generator?

If the budget forces you to look towards solutions other than buying a diesel generator why don’t you take into consideration having a second hand generator   ?

We can make a comparison between the pros and cons of the two possible situations:



When you know since the beginning that you won’t deal with it….

Having a generator or keep it in proper condition which would make it timely and safe use is totally useless.Having a diesel generator and not keeping it in good conditions is totally useless.

If you own something you , it’s vitally important to keep it in a good working order to avoid that it loses its value.

During our maintenance activities we often meet situations where the generators are almost new but completely abandoned because the proprietor doesn’t take care or the person in charge for the maintenance has forgotten to do its job. Well the classic stories that happen in several firms.

Solutions do exist:   maintenance contracts ,   Rentals  for short and long periods are solutions that avoid you to immobilize huge amounts that will lose their values with time.

To sum up the concept, I am inviting you to take into consideration the costs before taking any decision since one you have it you should look after it.

When there are more economical options

“I was thinking about cancelling my network provider contract and to install a diesel generator. Is it convenient?”


If your target is to save money by creating your own electricity burning fuels the answer is no and there is no need to mathematical calculations to prove it. Trust me, it’s not convenient. And that’s coming from someone who would gladly sell you one.

The alternatives to car-producing generator exist: they are renewable sources.Alternative solutions to diesel generators are the renewable sources.

Unfortunately, even in the case of an eco-friendly plant you should think about a backup power source. Guess what is it?

Andrea Orefice

The most compact and silent generator. The history of TP20K.

The market offers compact solutions, but  it is often about generating sets with two-cylinder engines at 3000 rpm, or  for other uses such as in construction or as a "hobby" where, in order to have compact dimensions, one must give up the comfort of quietness and convenience.

The element that often discourages the purchase of a professional generating set is the size - weight ratio compared to the electrical power.

There is a link between the size and noise of the generator which stems from the fact that a real silent generator  has several constructive requirements, that, for equal power, make it larger than other generating sets

To better understand this connection, we take into account that in a  real soundproof generator, the airflow is channeled in such a way that the noise can be better absorbed. In addition, the position and the type of materials constituting the silencer are very different from the great majority of generators that are improperly defined "soundproof" and are actually just containded in a canopy. In other words, they are placed in a frame or a cabin, with nothing that can absorb the sound other than the steel sheets .

Having clarified this issue, it becomes clear that it is not easy to reconcile noise and size without compromising performance. However, in recent years we have given much space in search of solutions to build silent compact generating sets without putting the customer in the position of having to give up something in terms of equipment and performance.

Building a generating set like the TP20K which has a length of only 140 cm and a width of 90 cm wouldn't be something outstanding except that the following equipment is provided as standard on it:

· It has 4 doors.

· It has a noise level of 65 dB (+/- 3)} at {2 meters.

· It has a  50 litres metal tank.

· A control panel mounted in the cabin.

· An internal silencer.

· An external fuel loading plug.

· It's totally automatic with AMF and battery charger.

Want to see it in operation? Here is a short video.

The idea of  the TP20K stemmed a year ago while we were developing a completely different product.

We were looking for the right solution for a customer who had really reduced installation space, where even a few centimeters would have made a difference. To do that we were willing to give up all the comforts that have distinguished us in these years. While we were testing all the possible solutions and modifications on the prototype, the "K" version came up thanks to a combination of ideas and technical arrangements.

Making Tesla K version was like packing a suitcase without giving up on your favourite clothes and shoes or being careful not to exceed the weight allowance.

The basic concept is that we wouldn't be giving up anything.

Generator with high-temperature resistant frame.

As is known, in a generator the heat spreads rapidly if they are not taken precautions to isolate thermally sensitive parts. 

The hottest components of a generator are mainly, but not only, the exhaust manifold, the exhaust pipe, the turbine compressor and the silencer. For these parts the most scrupulous manufacturers adopt the measures capable of limiting contact with hot parts and at the same time contain the temperatures radiated by the same.

Sometimes there are situations in which contribute to 'increase of a generator set temperature and the environment that hosts it there are external factors such as: the temperature at which the generator is in operation or the presence in the proximity of the generator group of sources of heat.

Some situations must be unfailingly avoided during installation, however, there are conditions that can not always be met. Take for example the case of an installation from 10 kVA generator, on open base, with from 50 liter tank incorporated. The customer must use the generator at a factory / store Pyrotechnic items, especially in service to a plant fire pressurization. Despite the full compliance of the generator with respect to the rules and to the system, it has been provided with a TY10 liquid containment tank resistant to high temperatures and direct flames.

Such a characteristic of resistance is possible thanks to the use of a frame with increased thickness of the plates and to a special paint finish with powder resistant to over 800 ° C for a limited exposure time.

This is not a useful finishing only to preserve the coating. Compared to the standard finishes, it slows down the spread of the heat under the same conditions and temperature.

This solution allows not only to contain any spillage of flammable liquids but to avoid the triggering in the presence of external heat sources.

In the past this special finish has been provided and tested positively for applications with a high direct exposure of the sun and on the control and switchgear.



Do Stabilized Generators really exist?


What comes to mind when you think of the word "Stabilized?"

Surely, the solidity of a bridge or stability can be compared to the constancy of a relationship, or even the stability of a ship sailing between waves.

The concept of "stabilized" is exclusively linked to the generator's ability to maintain stable values.

The most common questions that make our customers our customers:

Can I connect a Personal Computer to the generator set?

Can I power my audio system with a generator set?

How can I feed a latest-generation Astronomical Observatory?

If you're reading this article, you probably don't have an oscilloscope. You have to give a party on the beach and you're interested in knowing if you can connect your 20,000 euro system to the 299.00 Euro generator set that your cousin will lend you.

We deliberately leave out technical aspects of how important the waveform and other important factors are, as addressing them will not answer your question. We would rather focus on the practical sense of the matter.

Before we talk about stability, it is necessary to make a premise about the load that we are going to feed. Load means the user, i.e. the one we connect to the generator set.

Each load has its own distinctive characteristics, which should be analyzed before each application. In this article, we are not talking about power factor, waveform, load-step, etc., simply because they are topics that deserve to be dealt with separately. However, we keep in mind that the greater the load variations, the greater our stability problems will be.

Do stabilized generator sets exist?

The answer is No. There is no official classification to distinguish between a stabilized and unstabilized generator set. There are performance classes, but not a distinction between stable and unstable. However, this term is commonly used to identify generator set groups that maintain stable nominal values and others that do not succeed in this.

Inverter? Yes, but not always

generatori inverter

The most stable sets par excellence are the generators with Inverter technology. A generator set with inverter technology has a thermal motor that is not directly coupled to an alternator.

On inverter generator sets, there are some clarifications to be made:

An inverter generator set is not necessarily suitable for powering electronic equipment. Manufacturers often do not provide clear information about the waveform and its quality. So, be careful before setting up your photo set and powering your valuable equipment with an inverter generator without first verifying its suitability.

Inverter generator sets are commonly used for power ratings up to 6kW.

This last point, linked to the low power that a generator with inverter technology can provide, puts a limit to the scope of application and leads us to reconsider solutions that allow us to have stable, defined generator sets.

One might wonder, "Stable compared to what?" Stable with respect to the parameters set by the manufacturer, and above all, with respect to the characteristics of the users that we will feed, usually linked to the region of the world in which we find ourselves. (Voltages and frequencies are not the same worldwide.)

Voltage and Frequency.

A voltage is considered stable when it is 230V on a single-phase system and 400V in three-phase. We can consider a frequency stable when stopped at 50Hz. (With regard to the region of the world in which we find ourselves.)

The generator set may have at least two elements to stabilize the voltage and frequency values.

- The AVR

- The electronic speed controller.

AVR is the automatic voltage regulator. This is an electronic device mounted on the alternator whose main purpose is to manage the excitation and automatically adjust voltage and frequency according to the load. The voltage regulator is very important because it has a more precise response than old electromechanical systems and prevents problems, such as commuting.

The electronic speed controller is an electronic device mounted on the thermal motor, which regulates the motor speed according to the load. This device decisively influences the voltage and frequency value of the generator set, since the frequency is linked to the speed of the motor revolutions (1500 rpm = 50Hz).

Now you're wondering, but if a generator set has a rotation speed set at 1500 rpm, what sense does it make to have a speed regulator?

In this case, too, we do not want to go too far into the technical aspects of the subject we will be dealing with in the future. Rather, we prefer to respond with something as simple as possible.

The speed of rotation for the motor of a generator is set at 50Hz is 1500rpm, and this speed must be kept constant even when the generator goes under load, since the alternator exerts a torque resistant to the engine shaft according to the active power. Consequently, the speed regulator must act on the fuel flow rate to keep the speed constant.

The difference in stability that a motor equipped with an electronic regulator can give compared to a motor equipped with a mechanical rpm regulator is the response to load variations. The electronic speed controller provides a quick and precise response that cannot be compared to that of a mechanical regulator, and a quick response corresponds to smaller frequency and voltage variation.

Electronic adjustment of the engine revolutions.

For convenience, we can distinguish the two types of regulation in this way:

The mechanical rpm regulator tends to satisfy the load demand requested by the user. It may suffer, it loses its speed and then resumes regardless of the values that change suddenly.

The electronic speed regulator gives priority to the values that the generator set must respect, following them independently of the load that varies, because it loses the load, but does not deviate from the reference values that are considered stable.

Would you like to know what risks we run if we feed a sensitive load with a generator set without AVR and electronic speed regulator?

But above all, would you like to understand, in detail, how to correctly size a generator unit, taking into account the regulation class according to ISO standard?

Download our mini tutorial for free! Click on the following link, enter your email and you will immediately receive the tutorial in your inbox.


“Let’s cogenerate”! What is a "CHP", Cogeneration plant and how it works?

The world's first power plant (built in New York by Thomas Edison in 1882) was essentially a cogeneration plant because it provided electrical heat and power to Manhattan's buildings.

From a performance point of view, the generator is a machine that "sucks".

Indeed, all the generators have a poor performance because, to produce electricity, they waste enormous amounts of heat energy dispersed through the exhaust gas, the radiator and the natural irradiation of the hot parts of the engine.

cogeneratore orefice generators.jpeg

The cogeneration plant, also called CHP, allows the simultaneous production of electrical energy and thermal energy in the form of hot water or steam.

For years, cogeneration has been an exclusive technology of companies and large plants that consume huge amounts of heat, but today it’s a technology increasingly closer to small and medium-sized companies and even the private sector, due to the evolution of energy costs which has made cogeneration systems more competitive than ever before, and a technology that makes small plants more and more reliable and economically sustainable.

Most of the cogenerations operating in Europe are powered by low-cost fuels:

·        CHP plants using natural gas

·        Biogas CHP plants

·        Vegetable oil-fuelled CHP (palm oil, rapeseed oil..)

·        Syngas CHP (gas produced by pyrolysis processes)

·        Diesel CHP plants

In Europe the installations’ trend follows that of incentives, so the choice of which fuel to use is based on economic factors.

Companies that choose to produce energy with a CHP plant are those that consume large amounts of thermal and / or electrical energy, better if both.  Think of a hotel, shopping centres, sports facilities, dairies, these are just some of the major energy consumers who choose a CHP cogeneration.

The advantage of a CHP plant is not only in the cost of self-producing energy, but also in the energy independence that is achieved. The most virtuous and careful structures that we follow have chosen a triple power source: CHP plant + Emergency Generator + Electricity Grid. In this way, not only do they have a low energy cost, but they do not risk staying in the dark in the event of a CHP plant malfunction or during maintenance stops.

When is a CHP plant worthwhile?

The entrepreneur who chooses to install a CHP plant, wants to make profits by reducing costs, and has made one or all of the following evaluations.

He assessed the energy demand of his structure by doing an energy audit. In the event that electrical consumption prevails over the thermal consumption, assess whether there is a physical proximity between the CHP plant and any thermal user, bearing in mind that this must go in unison with the electrical one, while maintaining a certain flexibility, as the demand heat and electricity can be disproportionate to each other in some periods.

The actual convenience is finally assessed on the basis of the cost of energy by the supplier and the sale of the same with the introduction into the network. The advantage is certainly that of putting all the electricity that is not consumed into the grid, earning a profit.

Finally, the assessment is objectively influenced by the cost of the fuel and its purchase conditions, on which the market price fluctuates (the fuel, whatever it is, is subject to price variations) and to the possibility of deducting costs and excise taxes. .


Business Plan is not a "Fable".

When designing a cogeneration plant, the conditions that allow a return on investment within the terms set in the financial plan are to be considered.

Unfortunately,  the conditions resulting from the experimental calculations are not reflected in the real operating conditions and in general during the whole life of the CHP plant.

Even the best CHP plants stay off many hours a year for small or big problems. From direct experience in the operation of cogeneration plants we can say that a small component, even a simple temperature probe, or a sleeve is enough to force a generator to stop.

The business plan is not a fable, it is a tool to validate the financing of the bank, but it is above all the project that every entrepreneur should check and use to make further assessments on the investment time and duration of exposure that this involves. . With this we must not imply that a CHP plant is a nut to track, but only that the best of conditions is not said to be the most realistic. All this because the income statement is based on the incentives provided for the plant, therefore only costs are accumulated when the plant is stationary.

How does a CHP plant work?

Simplifying to the extreme, we can state that the CHP plant consists of two main elements, the Generator, in turn composed of engine and alternator, and one or more heat exchangers.

At a theoretical level, the exhaust gases emitted by the generator and the coolant used to cool the engine and keep the temperature constant during operation, are already potentially usable because they are available at high temperatures. In reality, obviously, it is not possible to use these fluids directly, as being contaminated they are harmful.

The exchanger is installed in such a way as to intercept the exhaust fumes, these give heat to another fluid (be it air or water or other fluids in the liquid state).

The most common exchangers are plate and tube bundle exchangers. In the first, the fluids at different temperatures exchange their thermal content through the appropriately arranged surfaces of the exchanger, the plates in fact.

How is a generator tested?

The term "test" defines a series of activities necessary to determine if a product is suitable for operation. Testing is often mistakenly misunderstood as the commissioning and the start-up of the product.

Let’s start by making a few clarifications: not all manufacturers of generators in the world have an equal and repeatable product testing process. Even those who adopt an ISO9001 quality management system do not have a standard test.

Some choose to carry out tests  on batches of products, while others choose to individually test each generator set, but with procedures that allow testing the functioning and not the performance of the generator. Then there are those who have chosen to adopt a complete test procedure that allows to test the functioning at 100% of the nominal power of the genset.

It is clear that the difference between these three test procedures affects the final result and the list price of the generating set.

With the sample test, usually chosen by large companies that produce large quantities of generator sets every day and in particular by all those companies that produce generators of small power, the risk of defective product is not insignificant. In fact, if the average incidence of the non-conforming product is 1%, in a company that has adopted this testing system it cannot be ruled out that this incidence is concentrated entirely in a few lots or even in the same lot.

Those who choose to test 100% of the production, but are limited to a functional test, can "guarantee" the conformity of the product in functional terms, but cannot guarantee the performance. For example, a 10kVA generator set is tested with a switch to the main parameters, but it is not subjected to an electrical load that can simulate the generator's behaviour in all its functions, so you cannot know if it will actually deliver the 10kVA for which it is sold on the market, nor can you be sure that when reaching the maximum power there are no technical problems.

In the end there are the manufacturers who choose instead to carry out a scrupulous test, which allows to verify the operation and performance of the generator, subjecting it to an electrical load to simulate the operation in the most severe condition of the generator.

The latter type of testing is indeed the most appropriate. the term "test" comes from the Latin cum-laude which means "work of art". So testing is definitely something that serves to establish if a product has been done well, to the letter.


Is it better to test the generator set directly at the installation site?

Some, explicitly ask for the factory test, while others take for granted that the test is performed at the site where the generator is installed. The testing is the responsibility of the manufacturer, who after a positive test issues a declaration of conformity. The ideal testing conditions can be reproduced only with suitable instruments present in the testing rooms and in particular with instruments equipped with calibration, however, even if  these equipment are available at the installation site, the operating conditions are hardly ideal for testing, especially the electric load connected to the generator.

A professional manufacturer, sets up the generator and tests it with a standardized and repeatable procedure. Here's how (synthetically) a general test is performed in a few steps:

• Check electrical connections, hydraulic connections and tightening.

• Starting with blank test.

• Try loading steps. (x% of nominal power up to 100% divided into different and increasing load ramps).

• 100% power test.

• 110% power test.

• Alarm simulation, instrument reading test, emergency stops ... etc.

During a test, the behaviour of the user, i.e. the dummy load used to simulate the user to feed, (usually a resistive load) is not comparable to a system with different loads and subject to anomalous voltages, unbalanced absorption, eddy currents, and so on and so forth.

From the point of view of the end user, there is no difference between factory testing and on-site testing, but in light of what is written above and considering the fact that the constructor of the generating set is not responsible for what is connected to the generator, the difference exists and is relevant.

Factory testing is a protection for the manufacturer and for the customer. If the generating set reaches the nominal power in the factory, while it presents anomalies of operation at the site of installation, it is possible to make evaluations to compare between the measurements taken during testing and those measured in service to the user.

Many companies allow to assist the testing of the generator, others are available to add specific test sequences required by the customer.

The test report must be requested during the signing of the supply contract, when ordering. In fact, many companies have a digital system for archiving tests and do not issue a paper certificate if it is not explicitly requested.


Testing is not just for the new generators.

I have a generator for a few years, which has been repaired, how can I be sure that it works like before...?"

The test is not exclusive for the "new" ones, in fact any generator can be tested with the same procedures adopted for a new generator. It is the only way to be sure of the functioning of a generator.

Let's take an example: Two years ago, I assisted as a counterpart, at the Expertise of  a Technical Consultant for the court. The engineer was in charge of determining whether a disputed Generating Set was in default or functioning normally.

Being also a Consultant for the Court of Cagliari, I immediately had doubts about the procedure adopted to determine if the generator set was working, in fact, the engineer with the help of an assistant, started the generator engine and seeing it turned on, he related to the judge that the generator was tested and was well functioning.

Now, to make a comparison, it is as if to check the functioning of a car for which you are complaining of a fault, you limit yourself to turning the starter key and turning on the engine to say that it works. A minimally qualified technician will take care of a test run and test the greatest possible number of instruments and accessories, reaching the maximum speed allowed to evaluate the effective efficiency.


Here is how UPS (Uninterruptible Power Supply) and Diesel Generator can work togheter.

When genset and UPS do not get along

In modern backup systems, it is not difficult to find systems that show the generating set and the Uninterruptible Power Supply in service on the same utility.

The configurations may be different. In many cases the generating set powers the Uninterruptible Power Supply which in turn supplies the user, while in other cases the UPS is independent of the Generator since it supplies a the non-connected part.

In the case in which a genset must supply a user through a UPS the installer finds himself dealing with the possibility that the UPS has tolerances relative to the electrical values that are incompatible with the generator.

The generator in operating mode has more or less stable values, specifically the voltage and frequency. The level of stability is not the same for all the generators, in fact, it can never be stressed enough, the generators are not all the same and are not distinguished only by electric power.

Usually the Uninterruptible Power Supply require a particularly rigid frequency and voltage stability, the reason is that the online double conversion UPS rebuild the voltage with its inverter. Therefore, the greater the instability of incoming values, the greater the work that the rectifier and the inverter will have to perform.

What happens when the power generator and the Uninterruptible Power Supply do not get along?

"When the generator is running the UPS issues an alarm ..."

Everyone is in crisis while trying to reason with the continuous "Beep" that haunts and prevents to focus on the solution.

When a UPS measures input voltage and / or frequency values outside the allowed limits (or rather, set by the manufacturer) it goes into alarm status and often an automatic bypass occurs.

For reasons still shrouded in mystery, the Customer and the Installer often prefer to make changes to the generator by intervening on the voltage regulator, rather than seeking a balance between the two products. This problem is nothing more than the result of incorrect sizing in the design phase, or an overly precise and rigid setup on the UPS.

It is also possible that the engineer did not consider the Harmonic component present in the system.

How to make peace between UPS and Generator.

Now that the problem is understood  we can move on to the solutions.

Mainly the problem is connected to the frequency oscillations of the diesel generator, in particular the rectifier present in the UPS continually senses the variation in the value and prevents the insertion of the inverter.

a)      The oscillations of a diesel generator are mainly due to load variations. The major problems occur when one or more loads are inserted. Example: The generator supplies a preferential line protected by UPS but also a part of the system consisting of motors and reactors. In this case, when the motor is switched on, a significant variation in frequency and voltage that could not be tolerated by the UPS will be inevitable.

b)     Many UPS allow to modify the intervention thresholds, therefore they allow to open the fan and frequency tolerated without affecting the quality of the output voltage.

c)      The generator intended for applications such as those protected by the UPS should be sized taking into account the class of the engine speed regulator. To learn more about this topic you can read an article about this topic and download the free material that we provide at the end of the article.

d)     Some manufacturers suggest the application of harmonic filters to the Uninterruptible Power Supply in order to reduce the harmonics (THD) to 10%.

e)     Do not be rushed to blame the generator or UPS, it is true that the harmonic distortion depends on the conversion system of the UPS but it is also true that the generator set has an impedance that is not comparable to that of the network.


The right generator for your UPS

The correct selection of a Diesel Generator destined to supply a Uninterruptible Power Supply begins with the definition of the operating logic criteria of the plant.

It is essential to know which loads in addition to the UPS will be powered by the emergency generator.

The main features involved in sizing are:

·        The overall power of the Generating Set.

·        The RPM regulator of the primary motor installed in the generator.

·        The power of the alternator.

The nominal power of the Diesel Generator

The nominal power of the genset is to be considered PRP, that is prime power of the ISO 8528 standard.

By definition of the standard, the PRP is the maximum power that the generator can provide during a variable power cycle.

When defining the power of the Generating Set it is important to consider the absorption values of the UPS during the recharging phases of the accumulator battery.

If you want more advices about that, please send an email to us:

If this article was useful, don’t hesitate to like it and share it with your colleagues ...!

Written from Andrea Orefice