Re: OT: How to Test Ungrounded GFCI's?
Bill Howatt
The lack of a ground for testing is a problem alright. Do you plan on doing the testing or having the renter do it? The latter would be a complication since my proposal sort of requires you having your wits about you. The renter isn't likely to do it anyway because I'll be virtually all people don't test their GFCIs even with the convenient test button available
I would, and there may be a better and safer way, is to make a non-metallic box with a 2 wire plug with only the hot connected. This assumes the hot side is wired properly on the receptacle or you have a non-polarized 2 plug that you can insert in either orientation.
Inside the box you would have connected to the hot wire a 18,000 ohm resistor which would give a leakage current of 6.7 ma at 120V. This should trip a regular GFCI but I've seen breakers rated at 10 ma which would mean a 12000 ohm resistor. The resistors should be 1 watt or more. It might be a good idea to use around the 10000 ohm value to ensure a trip if the voltage is a bit under 120V which it may well be. !0000 ohms would give a 12ma fault current at 120V. Granted this doesn't test the GFCI at possibly its most sensitive value but would eliminate false failure indications. The wattage should be 2 watts for 10000 ohms although since it is a momentary test the dissipation should not be a problem.
On the other end of the resistor, for some degree of safety, would be a normally-open pushbutton switch, and on the other side of the switch would be long wire with something like a crocodile clip for connecting to a ground such as a grounded water pipe, stove, dryer, .... . Pressing the push-button switch would then put the hot wire to ground through the resistor and long wire. NOTE: Pressing the switch would put 120V on the crocodile clip wire if it isn't well connected to ground and that is why this is method the requires you have your wits about you!!!
The long wire has to be able to reach a ground from any receptacle being tested. The biggest risk for shock is in the kitchen because of the availability of grounds that can be touched while touching a faulted appliance. Bathrooms and basements (washing machines, dryers, grounded cement floor). One of the worst shocks I got was from touching a live conductor while standing on the basement floor without shoes on!
Bill