I'm no expert on spas but it seems if you disconnected the heater terminals, power off of course and measured with a good ohm meter (not somthing like a Fluke T6 that only goes up to 1K) you should see a very high resistance between each leg and ground. My guess on the math, please correct me if I'm wrong, would 120/.005=24K ohms to trip a 5 miliamp GFI.
I recently read here that the GFI breakers have a higher tolerance, around 30 miliamps so that would be 120/.03= 4K ohms.
I guess that would assume a single point of leakage right in the middle of the element though.
With leakage right at one end of the element it would be 240/.005=48K for the 5 mili and 240/.03=8k for the 30 mili.
Would it be true that with a 30 miliamp GFI it should be possible to tolerate down to as low as 4K between a hot leg and ground before she blows?
Vince
