• Craig Drabyk

Emergency Power System PM Should Include Annual Pull-the-Plug Power Interruption Testing

Updated: Oct 18


Emergency and standby power systems are an important requirement for providing reliable backup and delivering electricity to critical building systems during a utility outage. These systems are typically tested and commissioned at project completion and are often required to obtain a certificate of occupancy by local authorities. As time goes on, however, emergency power systems can fall into disrepair due to lack of maintenance, human error, parts failure, or system alterations or changes, along with many other causes. Failure of these systems in an emergency can result in the failure of critical building systems and equipment, the cost of which can range from moderate to catastrophic.


For this reason, routine maintenance, system exercise, and operational testing should be performed on a regular basis to ensure that individual system components are working properly. According to NFPA 110 standards, recommended intervals for testing items such as EPSS components, batteries, ATSs, generator fuel, and breakers should occur at least annually and as frequently as weekly or monthly.


Additionally, many manufacturers, electrical and mechanical contractors, engineers, insurance providers, and local jurisdictions recommend or require annual “pull-the-plug” power interruption testing. Also known as loss of power response (LOPR) testing, this confirms that all generators and ATS systems will start as required in an emergency and that electrical distribution from the main service properly returns to normal when utility power is restored.


Equipment or systems considered critical to a facility’s operation and should remain emergency-ready at all times include emergency lighting, fire alarms, sprinklers, critical cooling or pumping systems, freeze protection, sump pumps, ventilation or exhaust systems, refrigerators and freezers, etc. Uninterrupted power systems, or UPS, may be required for programmable logic controllers (PLCs), building automation systems (BAS), process controls, and other critical circuits or loads. It is important that detailed PM and testing records be maintained for warranty purposes and insurance coverage in case of failure.


About Omni Omni Instrumentation & Electrical Services, Inc., located in New Jersey and Maryland, is a premier instrumentation and electrical contractor, providing superior total care solutions since 1986. Services include instrument installation, tubing installation, instrument calibration, control loop testing, startup and commissioning, power and lighting, process control wiring, BMS wiring, telecommunications and data wiring, fire alarm wiring, security wiring, process network wiring, and control panel fabrication. Omni Instrumentation & Electrical Services, Inc., is certified in Foundation Fieldbus, Profibus, DeviceNet and ASI-Bus installation.

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