The purpose of most generator sets is to provide a trustworthy source of power for your facility or business during an emergency situation when the power is out or not available for some reason. In the event of a power failure, there should be no doubt that your backup power source will kick into action and get you back up and running. But what happens when the power goes out and your genset does not operate the way it is supposed to? The results can often be costly and sometimes disastrous.
This is the reason why generator load bank testing should be a crucial part of your generator maintenance plan — and this testing should ideally be done each and every year. Load bank testing ensures that your generator will be:
- dependable and operational when the power is needed
- capable of generating the highest possible load required at any crucial point or time
What is Load Bank Testing?
A generator load bank test involves an inspection and evaluation of a generator set. It makes sure that all primary components of the generator set are in proper working order. To conduct a load bank test, artificial loads are put on the generator by bringing the engine to the recommended operating temperature and pressure levels. This is especially important for emergency generator sets that do not run very often and may not be exposed to carrying heavy loads on a regular basis. The general rule is if your generator is not exposed to more than 30% of its rated kilowatt load, you should have the generator load tested.
A load bank test ensures that your generator will run when needed so that you can count on it producing power during any kind of emergency that may arise. A proper load bank test will give you an evaluation of your generator at its full kilowatt output rating. Many generators don’t regularly operate at their full kilowatt rating. It’s very important that the generator produce the horsepower that’s required for it to run flawlessly when that power is needed, while maintaining the right temperature and pressure levels and allowing it to run for long periods of time.
What is Done During a Load Bank Test?
When a load bank test is started, an artificial load is placed on the generator. The test is timed and the kilowatt load is gradually increased in specified increments. Every time the load is increased, critical engine functions are measured at the highest possible levels for a sustained period of time. To complete the test, a load bank is needed (a machine with kilowatt rated sizes and battery type cables).
When a diesel powered generator is not used very often or is only run on light loads, it can experience unburned fuel and soot buildup in the exhaust system. This is called “wet-stacking.” Wet-stacking usually happens when the genset is not performing the way it’s supposed to. This may lead to damage or become a fire hazard and can even lead to the generator not working at all. During a load bank test, the generator is run at full operating power and temperature. This will cause any wet-stacking to burn off. Load bank testing actually serves two main purposes:
- It tests the generator to determine if functions properly and efficiently when needed.
- It removes any built-up carbon within the generator.
Advantages of Load Bank Testing
There are many reasons why gensets should undergo a load bank test on an annual basis, including:
- Confirming the gensets output capabilities as opposed to just starting it up on occasion.
- Finding problems now, instead of when an emergency arises, can be a major cost savings and prevent future breakdowns.
- Helps to avoid wet-stacking and cleans out any carbon deposits.
- Confirms that the engine cooling system will work efficiently under load.
- Makes sure that the genset will work properly when needed.
Load bank reports should include:
- Kilowatt Load
- AC Voltage
- Oil Pressure
- Amperage Rating
- Voltage Tested
- Any Additional Concerns or comments