Another 3 Phase question

[whoaru99]

Would be interested in hearing your theory why that is.

I'd suggest there is no such a thing as a nuisance GFI trip. Unless the presumption is GFI itself is defective, which we know in this case isn't the case, it is detecting leakage in excess of the threshold therefore doing exactly what it is supposed to do. I understand frequent GFI trips would be a nuisance but that's a secondary matter.

Again, if the guy wants to do it, it shouldn't hurt anything but it comes across to me it worked for a long time just as it is. Something has changed downstream of the GFI. Whatever "something" is is what needs to be fixed.

 

[toddalin]

I checked this morning and everything is still running fine. I figure eventually it will trip, but I can't do any more diagnostics until it does. At that point, I can test individual wires.

Could be nothing more than a build up of spider web in one of the motors. Alterntively, there is vibration, especially when the high speed pumps cycle, and a wire could get "scuffed." The spa has been in place running fine, as wired, for ~8 years.

 

[toddalin]

Just to follow up. Spa is still running fine and nothing has tripped. I closed it up a couple days ago, and no problems..., yet.

 

[fireprix]

What you need is a megaohm meter or motor insulation tester. You can test all components and wiring with it. You’d turn the power off and attach one lead to the component or wire and the other lead to ground. It will put about 500 volts through the component or wire and will tell you what the resistance is to ground in megaohms (1 megaohm = 1,000,000 ohms) Anything under 20 megaohms is a failure, up to 100 is questionable 150 and over is usually good. You cannot really do it with a typical multi meter because they do not produce enough voltage. And no it will not damage motors, heaters or wires. It can be used on anything rated at 120 volts or higher. It has very little current capacity and you are not actually completing a circuit.