Setting the Standard with NFPA 110
Whenever we hear thunder and watch lightning crack the sky, we all buckle down and await the brewing storm. As we watch the storm roll in, many of us run to check our junk drawers for flashlights and spare batteries, just in case there’s a power outage.
What happens at your office when a power outage occurs? Do you find your way to those extra flashlights in the dark, or do you have a back-up power source that turns on? If you do have an emergency power system, do you know how often it needs maintenance or an inspection?
The most referenced standard when designing a system, NFPA 110, covers performance requirements for emergency and standby power systems that provide an alternate source of electrical power when a primary source fails.
A system consists of the generator set, over-current devices, transfer switches, conductors that interconnect the pieces and fuel storage. NFPA 110 details proper installation, maintenance, operation and testing requirements to ensure the system operates correctly and efficiently.
There are three categories of classification for emergency power supply systems: class, type and level.
Class: the minimum amount of hours the generator set can operate at its rated load without refueling. For example, equipment in class 48 can operate for a minimum of 48 hours without refueling.
Type: the maximum time, in seconds, from utility outage until the standby generator supplies power to the load. Type 10 means that the system must provide power within 10 seconds of a power outage.
Level: table 5.6.5.5 of NFPA 110 sorts the potential effects of failures into levels. Level 1, for example, is used when failure of the standby system could result in loss of life or serious injury. Level 2 includes failures that are less critical to a person’s life and his/her safety.
All systems must be inspected weekly and exercised under load at least monthly, for a minimum of 30 minutes, to ensure proper upkeep. NFPA 110 also requires that circuit breakers be exercised regularly with EPS in ‘off’ position. Breakers rated in excess of 600 volts should be exercised every six months and tested every two years under simulated overload conditions.
All systems must be inspected weekly and exercised under load at least monthly, for a minimum of 30 minutes, to ensure proper upkeep. NFPA 110 also requires that circuit breakers be exercised regularly with EPS in ‘off’ position. Breakers rated in excess of 600 volts should be exercised every six months and tested every two years under simulated overload conditions.
Interested in learning more about this standard, or need to have maintenance, an inspection or testing performed on your building’s electrical system? We’d be happy to host a lunch n’ learn at our facility or have one of our certified electrical technicians visit your building.