Originally Posted by InTooDeep
So dryer outlets are automatically hooked up to prevent ground faults?
With double insulated appliances with a two prong plug there supposedly cannot be a ground fault.
With grounded appliances with a three prong plug the ground conductor carries virtually all of the fault current, and your body virtually none, since the resistance of your body is much higher than copper wire.
With ungrounded appliances and a ground fault and 120v to ground your body is assumed to pass up to 1/4th amp to ground, giving a skin/body/skin resistance of 120/(.25) = 480 ohms.
With ungrounded appliances and a ground fault and a GFCI your body will pass some current for a short time.
How much time? Max T in seconds = (20/I)^1.43, with I in milliamps (UL 943). 20 mA is about the max let-go current and you will be disconnected in <1 second.
For 10 mA, it's 2^1.43 seconds. You have a scientific calculator? My spreadsheet says this is 2.7 seconds.
You can check for GFCI protection.
Run a small 120v incand. bulb from either hot line to a known good ground. If it goes out and you hear a click somewhere in your house then you have it and then you need to reset the thing.