Load Bank Testing Generators – New Jersey Provider

What is Generator Load Bank Testing?


A typical commercial facility’s electrical load on a standby generator is often dispersed and unpredictable, therefore load bank testing is essential. A generator load bank test is the examination and evaluation of the electrical load used on a genset. Our load bank is a self-contained unit that applies controlled load on your standby generators. It consists of load elements with controls that allow an operator to incrementally step and vary the load. We offer our load bank testing service that will allow you to gain assurance that your emergency generator will supply power for an extensive period of time and perform as designed.

Why Load Bank Test? –  An Important Aspect of Generator Preventative Maintenance

Maintaining generator reliability depends on performing regularly scheduled load-bank testing. A load bank allow generators to be tested at their full capacity and ensures that your generator will be dependable and operational, as well as completely capable of the highest possible load it may be required to handle at any critical point in time.

A generator load bank test verifies that all primary components of the generator set are in proper working condition. The equipment used to conduct a load bank test produces artificial loads on the generator by bringing the engine to an appropriate operating temperature and pressure level. This is especially important for standby and emergency generators that do not run very often and/or may not be exposed to carrying heavy loads on a frequent basis. The general rule is – if your generator is not exposed to higher than 30% of its rated KW load then you should be considering a load test.
Generators are commonly sized as much as 30 percent over the kW rating of a facility to accommodate the surge of the building and equipment startup load. When a diesel engine powered generator is only run on light loads and is not used frequently, it can be prone to experiencing unburned fuel and soot buildup in the exhaust system. This is called ‘wet-stacking.’  Wet stacking is common when diesel engines don’t operate for extended periods of time with little or no load applied. Conditions such as wet stacking and carbon buildup in combustion chambers, injector nozzles, piston rings, turbo chargers, exhaust piping and silencers can develop and the genset is likely to perform poorly.

An on-site Load Bank test is an option offered by Innovative Electric that can be incorporated as part of your generator maintenance program.


Wet stacking is unburned fuel that accumulates in diesel exhaust. When wet-stacking occurs, the genset is likely to perform unsuccessfully, to endure damage, can become a fire hazard, and can even lead to complete failure.It can be detected by black discharge around exhaust connections or continuous black exhaust from the stack after warm up. Exhaust gas temperature of 275 degrees Fahrenheit must be maintained to avoid wet stacking. During a load bank test, the generator is allowed to run at full power and full temperature. Therefore, this will cause any wet-stacking to burn off. Also, with the increasing awareness of exhaust pollution, regular load banking is an important aspect on the generator owner’s part to minimize exhaust pollution in their communities.

When a load bank test is implemented, an artificial load is placed on the generator. The test is timed based on your requirements and gradually increases the kW load in specific increments. Each time the kW load is increased, the test measures and records critical engine parameters, the generator’s ability to handle the boost, and its ability to continue functioning at the highest possible level for a sustained period of time.  A full report is then provided to you for compliance with regulatory or engineering requirements.


  1. Do not place Load Bank next to anything that is affected by heat. The heat from a load bank exhaust air can damage objects or plants that are too close. Therefore, it is imperative that the load bank is situated in free air space for sufficient heating and cooling.
  2. The emergency switch-gear should be disabled to avoid unintentional transfer to facility load.
  3. The load bank should be connected to the load side of the generator breaker for optimal placement. Calculate necessary cable run based on distance between portable load-bank unit and cable termination point.
  4. Calculate number of cable runs necessary based on total amperage load that is to be applied to unit and amperage rating of provisional cables. Roll out essential cable based on above calculations, phase by phase to prevent cross phase connections.
  5. Notify the facility administrator of start time and estimated completion time.
  6. Confirm that all cables point-to-point have secure termination, proper insulation, and correct phasing. All cables should be color coded prior to installation to simplify verification.
  7. Start unit up at control panel and allow unit to come up to speed. Then, Power up load-bank and check load-bank cooling fan rotation and adjust as necessary. After 5-minute warm up period obtain base readings.
  8. Apply load accordingly based on type of test. Readings are taken every 15-minutes and are recorded.
  9. Readings during a load-bank test consist of the following:

-Time -Frequency (Hz), -Battery Voltage (DC) -Voltage (AC-L1, L2, L3), -Oil Pressure (PSI) -Amperage (AC-L1, L2, L3),
-Coolant Temperature -Power Factor (1.0), -Ambient Temperature -kW, -Exhaust Temperature – Load Percentage

  1. Upon completion of cool-down period load-bank is powered down and unit is turned to the “OFF” position with the circuit breaker open. Allow a 30-minute cool down at the end of the test with no load.
  1. A Log is recorded and produced for examination and validation that the load test was properly administered.

Conclusion of Load Bank Testing

Load bank testing should not be considered a choice, but rather a critical element of your emergency preparedness plan. The test should be performed annually for standby applications. During weekly exercises, the engine will not reach manufacturer’s recommended operating temperatures. Therefore, facilities should make sure this is included as part of your annual maintenance plan.

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