The Home of Diesel Generators

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Welcome to our Frequently Asked Questions page where we will answer all of your questions on Diesel Generators, Electric Generators and a vast array of other well used terms and topics. We also have a detailed Knowledge Centre to further enhance your understanding and many products to choose from on our used generator and new generator pages.

  • It is vital to regularly check your generator to prevent breakdown. Below are some simple observations that can help keep your generator running smoothly (please note any further works should only be carried out by an experienced generator engineer):

    • 1.   You must check fuel levels, running out of fuel not only causes a breakdown but can cause the engine to suck in dirt from the bottom of the tank resulting in a filter blockage.
    • 2.  Ensure coolant and oil levels  are ok and top up if necessary.
    • 3.  Visually check the engine for any cracking hoses and fuel/coolant leaks.
    • 4.  Check your batteries are in good condition. Winter conditions and regular starting can cause batteries to deteriorate.  It is a good idea to test your batteries charge to ensure they are still ok. Battery chargers should be connected when a generator is not running for an extended period.
    • 5.  If your generator is used as a standby application, a weekly run will help identify if there are any problems.

    FW Power can undertake a 75 point service inspection on your generator to ensure yours is ready to run.  Call us today to find out more.

  • A common misconception  is that diesel generators are dirty, environmentally unfriendly and even expensive to run. Thanks to the invention of red diesel and advancing technologies, diesel generators can now run extremely efficiently and be a very cost-effective option. The simple answer to the question, however, is that a diesel generator is the most reliable backup power source currently available for extended running periods. Generators can start up in seconds providing a steady stream of power continuously.

    FW Power can provide Generators to suit most peoples budgets –  Call us today to find out more.

  • Generators are rated by kVA, this indicates how much power the generator can produce. Mechanical engines are rated in KW’s or Horsepower.

    kVA = Kilo Volt Ampere.

    1 kVA= 1000 Volt Amperes (VA). A VA is the voltage times the current feeding an electrical load.

    1 kVA = 08 KW’s (electrical)

    If you are unsure of what power requirement you need FW Power offer a simple guide to sizing or if the application is more complex we can attend site and look at sizing for you. Additionally we have a more indepth guide to kVAClick here to view.

  • A load bank is a portable device that is used to mimic the load on a generator. A load bank tests the generators operational performance at every stage i.e. 20%, 50%, and up to 100% load. This ensures the generator is capable of doing what it is required to do when the need arises. It is a crucial test for standby generators, especially as faults can be identified and rectified before the time arises when you need your generator.

    FW Power offers a full load bank test alongside our service contracts, we can however on request attend site as a one-off and undertake a full load bank test too. Please give our friendly office a call who will be able to help arrange a visit.

    Additionally, all of our used generators undergo a full load bank test, which gives you peace of mind the generator can produce its rated power.

  • Single phase :

    Consists of 3 cables: Live, neutral and earth. Typically the voltage is 220-240 Volts. Domestic houses have single phase supplies.

    Current will flow through only the live wire and there will be one return path (neutral) to complete the circuit.

    Three phase :

    Consists of 5 cables: 3 live ( L1, L2 & L3), a neutral and an earth. Typical voltages are 400-415 Volts between the live cables ( eg. L1-L2) and 200 -240 Volts between the live and neutral. hence a three phase system is often given the voltage as 415/240V.

    Both single phase and three phase power systems refer to units using (AC) alternating current electric power.


    For more information please take a look at our guide on differences between single and three phase  , you may also find our  other guides helpful such as  view our guide on Generator Sizing and Installation. 

  • Yes, we work alongside a finance company that offers competitive packages. We also welcome customers using their own choice of finance company too. Each finance package is individually tailored therefore please call our office for more information. 01270 821419.

  • An ATS is an Automatic Transfer System. It is used alongside standby generators allowing generators to be started automatically. When the mains is healthy it provides power to a building. When the mains fails an ATS senses the failure and sends a signal to the generator to start and transfer power to the building when it is safe to do so.


    FW Power have a helpful guide whch details how and what an ATS is – click here to view.

    Why not also view our Knowledge Centre where we add lots of useful informational on products including ATS’s.

  • All generators have an earth cable connected which goes back to the main building earth rod. However, in the event of a building earth failure, there is still the possibility that the acoustic enclosure or base frame could become live during a generator fault. It is the job of an earth rod to ensure that this faulty current goes immediately to earth.

    If there is anything you are unsure about with regards to your installation, contact us and we will be able to advise.

  • kWe = Kilo Watt Electrical. In 3 phase generators it is the kVA x 0.8.

  • Most engine manufacturers recommend service intervals of between 200 and 500 hours when the fuel filter, oil filter, and oil should be changed. For a new generator, a few manufacturers have an initial 50 run period for the first service.

    For Standby generators we recommend two service visits per year to sit alongside the weekly checks. We class these as a major and minor. The minor is a visual check of the generator whilst stationary and running, topping up any levels as required. The major covers all of the points of a minor but can also incorporate oil, filters and coolant changes as required.


    For a more indepth idea of what FW Power offer view our page on 75 Point Service Inspection for more details.

  • When looking at what type of generator is best  for you firstly you need to asses what you need it for.

    Petrol Generators


    Petrol generators are usually a better option for  a small infrequent power requirement such as powering a caravan ,market stall or even powering a mobile jet washer.  Petrol generators are offered  in much smaller kVA ratings to suit these operations. To an every day user petrol is a cheaper fuel than white diesel, petrol generators are much more compact and are often mobile to suit their users needs.

    Diesel Generators


    That being said most industries where power requirements are higher than 10 kVA will usually opt for a diesel generator. Diesel generators run on Red Diesel which is cheaper than petrol. Diesel engines don’t have to work as hard as petrol engines to get the same power output which means like for like a diesel generator will usually last longer, cost less to run and take longer to depreciate in value than it’s petrol rival.

    FW Power supplies new and used diesel generators from 10 kVA  up to 2900 kVA.


  • This is a very common question we get asked and understandably so. Depending upon your needs noise can be a very important factor when looking to buy a generator.

    There are two common terms when talking about generators that you will probably hear us mention: ‘silent’ and ‘open skid’.  The word silent is used for generators that have an acoustic canopy,  however this does not mean that the generator makes no noise at all and  the word ‘silent’ may be a little misleading. There are  various different types of canopies produced that can reduce the noise of a generator.  The most effective type of generator when it comes to reducing sound are called ‘whisper generators’,  a very high spec but be warned these comes with a much higher price tag. These type of generators are often used on TV and film sets where noise is a very important factor.

    ‘Open Skid’ sets are just that, open and sat on the skid. No sound attenuation and they will be significantly louder than a silent generator. If noise isn’t a worry then open skid sets can be a great option. Have a look at our used generators page where we have some good cheaper generator options for you.

    Noise is measured in dBA ( A-weighted decibels) and generator manufactures  will give generators  a dBA rating at a set distance for example 77 dBA @ 1 meter. The easiest way for us to explain what this sounds like is by showing you dBA ratings of common every day sounds that hopefully you can relate to. Have a look at our info-graphic chart for more information.

    dBA sound level chart to explain noise levels of common everyday sounds

  • Synchronising in generators is when multiple generators or generators and the grid work together. Synchronising refers to the voltage, frequency, power factor all being the same i.e in sync with one another.


  • Base Load is the portion of load of a generator or building which is constant. Alternatively referring to a constant generator output when in parallel with the grid.

Knowledge Centre

For more information on diesel generators, alternators, engines, manuals, how to guides and much more please view our information centre. New useful information is added weekly to help guide you or answer any questions you may have.

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How does a generator work? Why should I choose a Diesel Generator? What is kVA? These are just a few example questions FW Power answer in our frequently asked questions section. We cover all popular questions on generators and alternators from installation, commissioning to servicing.

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