David G. Loucks, P.E., Eaton Corp.


Arc Flash & Electrical Safety October 15, 2007

Making sense of time-current curves

An electrical fault should be cleared as fast as possible while containing the outage to the smallest possible area. This requirement, known as 'selective coordination,’ is met when overcurrent protective devices installed closest to the fault open before protective devices installed upstream. One method of ensuring selective coordination is to examine each overcurrent device’s time...

By David G. Loucks, P.E., Eaton Corp.
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