Generator Load Bank Testing

Load Bank Testing

At Diesel Generators Direct, we don’t stop at supplying the highest quality diesel generators for prime or backup power for a range of purposes and industries from Data Centres to Farms and everything in-between. We also strive to ensure that our customers get the very best value for money. Not only does this mean ensuring that we supply quality generators at the best prices, it also means that we educate our customers to make sure that they’re using their generators as effectively, efficiently (and of course safely) as possible.


This includes ensuring that our customers know which tests should be carried out on their diesel generators, why they’re important and how to carry them out. A Load Bank Test ensures the efficiency of your genset.

A generator load bank test involves a series of examination and assessments on your diesel generator to ensure that it will function optimally when you need it most. It ensures capability and battery autonomy as well as making sure that all the generator’s primary components are in proper working order under loaded conditions.

Load Bank Testing uses a piece of special equipment (the Load Bank) to produce artificial loads on the generator by bringing the engine to the right operating temperature and pressures.

We need to consider the intended function of a diesel generator. It needs to be able to kick in immediately when your mains power supply fails to prevent a potentially catastrophic loss of function and data for your business. Because your diesel generator will, by its very nature, likely be used very rarely, you need peace of mind that comes from ensuring that your generator will kick in without fail even having lain dormant for long periods of time.

This is especially important if your generator will likely be needed to carrying heavy loads on a frequent basis. By rule of thumb, if your generator is not exposed to higher than 30% of its rated kW load you should be carrying out Load Bank Testing.

Load Bank Testing is necessary in preventing issues which may lead to a slowness or loss of generator function. The most common of these is Wet Stacking. This occurs when diesel generators only operate infrequently and / or are only subjected to light loads. Over time, deposits of soot and unburned fuel can start to collect in the exhaust system leading to Wet Stacking. This can cause the diesel generator to perform erratically or can even result in damage to the generator’s internal workings. Load Bank Testing can burn off these fuel and soot deposits and reduce the risk of Wet Stacking. But this is far from the only benefit, which brings us to...

In order to be at its most effective, Load Bank testing should be carried out annually. When it is implemented this regularly, generator owners get to enjoy the following benefits

  • The generator’s capabilities are verified without the need to routinely starting it up.
  • Issues that could interfere with performance can be identified earlier, resulting in prevention of productivity loss and significant savings on repairs.
  • The generator is kept clear of carbot (soot) deposit and the risk of Wet Stacking is mitigated.
  • Users are assured that the engine cooling systems will perform well under the required load.
  • Provides a much more reliable indicator of performance than simply firing it up. Just because your generator fires up okay doesn’t mean that it can handle your load.
  • Users have complete peace of mind, knowing that their generator has their back when they really need it.

Load Bank testing is designed to provide peace of mind for generator users, and as such checks all of the factors that are critical to efficient and reliable operation and diesel generator longevity. While we’ll get into the methodology of how the tests are carried out shortly, the factors checked include;

  • Oil Pressure
  • Hertz
  • kW Load
  • AC Voltage
  • Amperage Rating
  • Voltage Testing

So, now that we’ve discussed what the importance and the benefits of Load Bank Testing and what gets checked during the process, let’s take a look at how it is carried out.

Whoever supplies your load bank, it should be supplied with suitably rated cables. These enable it to be placed a maximum 20 metres from your diesel generator terminals or power distribution unit (PDU).

Load banks are made with heavy heating elements and fans for cooling, so allowances should be made for heat dissipation and noise attenuation while the tests are carried out. Make sure the test is carried out in an appropriate location with no sensitive alarms, sprinkler systems or, of course, people at work in close proximity.

Measurements are taken during discharge which are used to determine battery autonomy and overall system performance. A Load Bank Test will also provide identification of any problems with the generator and Uninterrupted Power Supply in real time, indicationing actions that should be taken to remedy the issues.

For standby diesel generators, a Load Bank Test is particularly useful as it not only indicates the engine’s ability to provide enough power it also ensures that the alternator has the capability to provide the required voltage stability. It also ensures that all components are working together to create a stable frequency and efficient performance with correct oil and fuel pressure. As the testing process is carried out by the load bank, carbon deposits will be burned away from exhausts, engine casings and pistons.

There are many services out there which provide a comprehensive Load Bank Testing service. This is recommended for busy and time-poor business owners. Because Load Bank Testing is so very important, it’s highly recommended that you rely on a trained professional to carry it out properly. What’s more, Load Bank Testing can also reduce system resilience, discharge batteries and represent a risk for connected loads. With this in mind, it’s best carried out outside of normal working hours.

This will minimise the disruption caused by testing while ensuring you peace of mind. If you are looking for a generator set to protect your business from a power cut, power failure or a power outage or for any other reason then get in touch with us at Diesel Generator Direct, we’ll be more than happy to assist you in sourcing the right power solution for your requirements. Ladies Hour