Arc Flash & Electrical Safety News
Blog Author Steve Hudgik
Friday, March 29, 2013
Arc Flash Detection Technology
How To Specify An Arc Flash Relay
"One way to defend against arc flash is to retrofit electrical cabinets with arc flash relays, which reduce arc duration by sending a trip signal to the upstream device faster than conventional over-current relays, thus limiting the incident energy and protecting workers from hazards. In many cases, the protection provided by an arc flash relay can reduce the level of PPE required for compliance with NFPA 70E safety standards and OSHA workplace safety requirements."
Topics covered in the article include:
- How an arc flash relay works
- Where to install arc flash relays
- Arc flash relays and power analysis software
- Arc flash relays and zone identification
- How long of a delay?
- What to look for in an arc flash relay
Read the article in Consulting-Specifying Engineer
Using Fiber Optics In Arc Flash Detection Applications
"The primary components of an arc flash detection system (light and current detector) are the arc monitor unit, control unit, optical detector, current detector and current transformer. The control unit receives signals from both a high-sensitivity light detector and the upstream current transformer, enabling it to determine whether to trigger the circuit breaker. Clearly, this signaling process must be both fast and reliable to minimize danger and damage. Fiber optics, with its inherent speed and EMI immunity, make it a perfect medium for an arc flash detection system."
Read the article in Electronic Design magazine.
See A Video Demonstration of Arc Flash Detection Using Fiber Optics
Engineers must consider arc flash prevention in the electrical systems. How important is timing?A post on the Consulting-Specifying Engineer magazine's we site raises the question of timing. The post is called "Timing Is Everything." The opening paragraph poses the question:
"Because an arc flash relay depends on an existing circuit breaker to interrupt the current, does it make a difference in overall reaction time? And if the relay must wait until an arc forms, will the relay take longer to trip than the circuit breaker would trip on its own? Finally, how does the reaction time of an arc flash relay compare to an overcurrent protection relay?"
The question is, do arc flash relay actually work? What do you think?
Read the Consulting-Specifying Engineer post here.
posted by Steve Hudgik | This Arc Flash Post and 0 Comments |