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GFCI Query

D

Den Murray

Jan 1, 1970
0
Hi Group

It's my understanding that if a ground fault circuit interuptor is miswired
with the polarity reversed, then the GFCI will not trip. Is my
understanding correct, and if so, why is this. Would this apply equally (I
assume that it must!) to portable (plug-in) GFCI's?

Cheers

D
 
D

deanmk

Jan 1, 1970
0
Gerald Newton said:
Try:
Fundamentals of Ground Fault Circuit Interrupters
at:
http://www.electrician.com/electa1/how_gfci_works.htm
Gerald

I good write up on how a GFCI works, however the statement that a "...GFCI
opens the circuit and limits the current to no more then 6 ma..." is not
quite accurate. There is nothing in the GFCI circuitry that limits
physically limits current. Your write in the second paragraph and the TCC
graph for the LM 1851 shows a fault current of 200ma @0.02 sec is possible
before the device would trip. Maybe a minor point, but in the past I have
had to caution workers that were using power tools at heights that the
initial shock may cause them to lose balance or drop the tool both which can
have serious consequences.

Mike
 
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