A load bank provides a dummy electrical load for a connected device. Load banks can be used with uninterruptible power supplies, energy storage systems and generating sets to in place of a critical load during commissioning, factory acceptance testing, sit acceptance testing and/or preventative maintenance. A load bank can be sized or set to deliver a set kW load that can be used to validate the electrical performance of the power system without risk to the critical load. The load bank is usually reactive and dissipates the resultant energy as heat.