Grounding Whirlpool Tub

[Chuck B]

Installed a Pearl Bath whirlpool tub with heater. Manufacturer requires 2 20-amp , 120v GFI protected dedicated circuits. In their instructions a #8 ground wire is to be bonded from pump motor to cold water copper pipe. However the electronic controller which the pump motor plugs into, and then you plug the controller into the GFI receptacle, malfunctions and is ruined. A service tech came out to verify this common occurrence. He installed a new electronic controller and advised me that the ground wire had to be eliminated as that caused the problem but I was still protected by the GFI. I called MAXX, the Canadian company that manufactures them and their "expert" concurred with the tech. Thoughts on safely operating it without the pipe ground and reliance on the GFI? Thanks.

 

[Jadnashua]

There should never be any current on the safety grounding wire in the circuit. The fact that there may have been, to me anyways, indicates a design fault or a device failure. But, if you understand how a GFCI works, it should protect you even if there is no ground, other than possibly from a lightning strike while sitting in the water. A GFCI trips based on there being some current leaking into something other than the two normal current carrying wires (on 120vac, those are the hot and neutral). Any current imbalance greater than about 5ma between the two wires (indicating it leaked somewhere it was not designed to go), shuts all power off to that circuit past the GFCI. ALL power should return to the source - any that leaks out is a fault - a GFCI measures that they are balanced, and if not, trips, turning off the power.

 

[Sponsor]

 

[ActionDave]

Hot tub tech support people provide some of the worst information in the world. While there is indeed a connection between the pump motor and the control panel there is no part of the frame of the motor or the cold water pipe that has anything to do with any of the electronic controls or making the motor run.

I don't doubt that the hot tub company is having trouble with electronic parts failing since they use the cheapest junk available. They are blaming the bonding wire to save face. Ignore them. Don't back down on making them honour their warranty though.

 

[JWelectric]

Next time you talk with the manufacturer or service tech ask them if the NRTL is aware of this problem and then let them know that you are advising the NRTL of the problem. Once you do this I promise that they will resolve your problem