A load bank is a device which develops an electrical load, applies the load to an electrical power source and converts or dissipates the resultant power output of the source.
The purpose of a load bank is to accurately mimic the operational or “real” load that a power source will see in actual application.
Consequently, a load bank can be further defined as a self-contained, unitized, systematic device that includes load elements with control and accessory devices required for operation.
Whereas 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