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Re: GFCI's ELCB's etc




Someone wrote:

 

"Hmm. That's strange. GFCIs should not need to be manually reset if they
loose power. I suspect that your GFCI is seeing a false ground fault when
the power fails (or returns) and is tripping due to that."

 

Not so, actually.  GFCIs that might be used for power tools are designed so that that they must be manually reset to "ON" if there is a power outage.  The reason for this is to prevent a situation where, for example, the power goes out momentarily on, say, a circular saw (or drill or impact hammer or whatever), the worker walks over to check if the cord came loose form the AC socket, and while he or she does so, the power comes back on and the saw restarts unexpectedly.  You can think up other dangerous scenarios--OSHA and other safety agencies have.  In fact, GFCI cords that do not need to be manually reset are prohibited from construction job sites under various state and/or federal regulations.  So almost any GFCI protected cord that you buy at, for example, Home Depot, trips "OFF" if the power stops.  GFCIs on some other cords, and GFCI wall sockets generally do not trip under an outage because the likely circumstances of use are different.  In fact, GFCI devices that are used for life support equipment (such as in a hospital) must be designed so that they do not need to be reset if there is a power outage.

 



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