Arc Flash & Electrical Safety News
Blog Author Steve Hudgik
Tuesday, August 12, 2008
System maintenance a key part of arc flash safetyAn article in IMPO Magazine, written by Joseph Weigel of Square D Services, Schneider Electric, discusses the important role that electrical system maintenance plays in protecting against arc flash.
Fault clearing time is central to mitigating the danger posed by an arc flash. However, without proper maintenance, upstream overcurrent protective devices may not be able to respond adequately in the event of an arc fault. Weigel writes,
When these devices are not maintained on a regular basis, their clearing time may increase, allowing more energy to be released in an event. If maintenance is deferred long enough, it may result in a worst-case condition that may render the device completely inoperable, meaning it will not open to clear a fault of any magnitude.
An improperly maintained electrical system may look safe on paper, but pose significant dangers in reality. Malfunctioning protective devices can greatly increase the incident energy released by an arc flash; devices which don't function at all may as well not exist.
NFPA 70B, "Recommended Practice for Electrical System Maintenance," provides a useful guide to ensuring that protective devices maintain full functionality. Unfortunately, NFPA 70B compliance is far from universal, as it is a voluntary standard not required by OSHA.
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