Diesel-powered generators are principal components in emergency backup power systems. Should they fail during an emergency, power for life-safety, generators critical, and operational loads could be disrupted. To ensure gen-sets perform as designed, periodic testing under load is required.

At some facilities, building load can be used to exercise engine-generators. However, because building load is variable, and testing can sometimes be disruptive to power distribution systems and load equipment, building load may be insufficient to comply with testing requirements, particularly during “off-hours” when testing problems would be least likely to cause disruptions.

Test programs are often performed by applying loads using loads banks. These offer users the ability to apply precise amounts of load for any desired duration. They also offer flexibility to schedule tests at any time of day, even during periods when building load is below 30% of generator nameplate value. As a result, load bank users can meet test loading requirements independent of a building’s real-time power usage.