Why does your GFCI trip when you plug in the refrigerator?

Answer 1

A GFCI trips whenever it senses a grounding problem. Not grounding the outside surface of radios, fans, fridges, metal lamps and hand tools can put 120 volts on the device where you can touch it and possibly be killed.

The GFCI trips so you will not be killed. Best to have an electrician check out your fridge. If it is OK, then the GFCI may be At Fault.

Answer 2

In many cases motors will trip GFCIs. This is less of a problem with the increase in motor inefficiency but very often still with refrigerators. You need to replace your outlet, assuming it isn't a counter top outlet, with a normal one or, if it is piggie backed onto a GFCI up the line, remove it from that circuit.

As to your question of why, I only know that somehow, probably through the motor's capacitor, your refrigerator pulls more current on one wire just fractions of a second before the current returns on the other. This current imbalance is what trips a GFCI.