A load bank is a device designed to provide electrical loads for testing various power sources. Load banks are also used to provide additional loads to diesel generators to ensure the engine fully consumes the fuel in the combustion process, reducing “wet stacking” problems.

The load bank develops an electrical load, applies the load to an electrical power source, and converts or dissipates the resultant power output of the source. The load bank should mimic the operational or “real” load which a power source will see in actual application.

However, unlike the “real” load, which is likely to be dispersed, unpredictable, and random in value, a load bank provides a contained, organized, and fully controllable load. A load bank can be further defined as a self-contained, unitized, systematic device which includes both load elements with control and accessory devices required for operation.

Where the “real” load is served by the power source and uses the energy output of the source for some productive purpose, the load bank serves the power source, using its energy output to test, support, or protect the power source.