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The ground fault interrupter shuts off the power to my garage. I measured the resistance between hot and neutral and it was about 15 ohms. Is there a short circuit?

Hi William,

Thank you for your question regarding Ground Fault Circuit Interrupters (GFCI), it is our pleasure to help.

If your GFCI is tripping, it indicates a short of some kind between the neutral and the hot wire.  This is a very serious and life threatening situation and should be rectified by a licensed electrician right away.  Not only could someone get electrocuted, but the property is at risk of fire as well. 

If your circuit breaker is off, the hot and neutral wire should measure as an “Open” (massive resistance) when measured with a resistance meter.  If the circuit breaker is on, we are not sure how accurate a resistance reading would be given the 120-volts that would be on the line.  We would not trust any resistance reading taken with the line energized.

If you have physically removed the GFCI outlet and are measuring the resistance across the two terminals, the resistance meter should read “Open” (massive resistance).

Keep in mind, that GFCI outlets tend to fault due to what is plugged into them.  Does the breaker trip regardless of what is plugged in?  Take a lamp or something other than what you typically plug into the outlet and see if it still trips the GFCI.  Drill motors and other high-current devices can sometimes trip GFCI circuits due to the large current draw they have at startup.  Also, old surge protector strips can cause GFCI breakers to trip.  You should go through your home and replace any of the low-cost surge protector strips if they are older than a few years.

We recommend you contact a licensed electrician ASAP.  There could be some other very serious issues going on with your system.

Best regards,

The Engineering Team at E&S Grounding Solutions


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