Hi Gang, New to me 1998 Coast Spa tub with Gecko TSPA-1 pack in mint condition. Here are the particulars... TSPA-1 with LCD push button control panel 6.5HP pump #1 4.5KW heater Ozonator No pump #2 or blower This is a new installation with a GFCI breaker in a dedicated sub panel, all wired correctly. Upon application of power from the main panel in the house, the GFCI trips instantly. I went through and disconnected the heater, no change, the pump, no change, the ozonator, no change, still trips. Decided to measure the blk/red wires to ground and neutral to see if I could see any leakage and what I found was 13 ohms from blk to wht wires. Probed around on the cct brd and found that the little power transformer that supplies 12 and 24VDC to the ccts, relays etc, gets it's primary power from 120VAC, blk and wht wires. Now when I pull the plug for this transformer, and reconnect the pump heater etc. the breaker is happy. My thought is that the little transformer is only drawing from one side of the 240VAC line and thus causing an imbalance or current flow in the neutral. Am I thinking correctly? But how could the tub work with a GFCI if this is wired like this. " title="Crying or Very sad" /> There must be something I'm missing here. " title="Idea" /> Help please. Cheers Paul

You've probably got a few 110v components on the tub. Your topside control, for instance. Lots of tubs use 110v blowers or ozonators on 220v installations.

The problem seems to be the transformer itself.

HI,

Thanks for the reply. Good thought, but I unplugged the transformer, and just plugged in the primary side i.e. the 120VAC side and left the secondary low voltage side off, the transformer is removed from the panel and is sitting on a piece of wood, insulated and isolated from everything else, just those 2 wires, and it STILL trips the GFCI. I'll try replacing it but I doubt that this is it.

Any other ideas?

Cheers

Paul

I'm not sure I understand. It seems like you're saying the GFCI stays on when the transformer is disconnected completely:

And that when the supply side for the transformer is plugged in with no load on the low voltage side it trips the breaker:

So that would leave us with the breaker only tripping when the transformer is connected to the board, right?

Yes, you have got it 100%. That's exactly the scenario. I have other transformers around the shop that I will try to see if it makes a difference.

I may be misunderstanding how or what GFI breakers do. I thought they monitored the current in the neutral but maybe it's the difference between the neutral and ground, rather than neutral and hot.

Arg. I'll get it yet.

Thanks

Paul

Hi gang,

Well, it was only a flakey breaker. I put in a new Square D GFCI in the sub panel and it works 100%.

Thanks for the ideas.

Cheers

Paul