A load bank is an electrical apparatus used to verify the performance of an electrical power source. The most common application for the equipment is to provide an exercise "load" for standby emergency generators. These emergency generators are typically installed at hospitals, hotels, office buildings, skyscrapers, water treatment facilities, data centers, large retail facilities, and other such sites. The load banks provide a precise and stable electrical load for the generators. The electrical load created by load banks allow verification of the performance of the generator on a scheduled maintenance interval. Many other applications for load banks exist other than standby generator testing. The generator manufacturers require load banks for research and design programs as well as production testing. The military utilizes load banks in various applications such as testing of power supplies and generators for aircraft, frequency convertors, submarines, and missile defense systems. Computer and network Uninterruptible Power Supplies (UPS) also require load bank testing of both the inverter and battery inputs.