I have a Caldera Kauai, 5 yo. Everything was working fine, then the original heater relay board shorted out in May. I bought a replacement from spastore.com & installed it myself in June. Model is Invensys IQ 2020. Now, I have a hot--ground ground-fault when I connect the #12 AWG wires from the 20A breaker. I've had a repair tech from the business that sold the spa to me out to fix it but he says he doesn't understand what's going on (he isn't coming back). He tried a new heater relay board--same problem. He tried an entire new electronics pack--same problem. Put the original board back in-same problem. He unplugged all the pumps & lights intending to plug them in one by one until the breaker tripped, but the GFI tripped even with all the components unplugged. The GFI breaker will trip as soon as the hot (blue) line touches its terminal block connection. The breaker stays in with only the red and ground lines connected to the new relay board. Connections from the 30A breaker don't have any affect on things.

I'm about at my wit's end. What's left that I can do that might fix this?

Couple things to clarify:

The relay boards come with jumpers in them for 110 volt tubs, did you remove them?

Was the tub running since June and just recently started tripping or are you just getting it going now?

You didn't mention the heater directly, did you disconnect that to see if it still trips?

Can you take a picture of the wiring and post it?

Dan--Per the instructions, the power jumpers were removed before the board was installed.

The tub has not run since the original heater relay board shorted out in May. But, it is filled with water.

All the peripherals the main board controls, including the heater, were disconnected with the intention of reconnecting them one-by-one until the breaker tripped as a way to find the offending component. But the breaker trips, even with all the pumps, heater, lights, etc., disconnected so there wasn't any way to reconnect things individually to find out which one was the problem.

I'll upload a picture of the controller and the wiring as soon as I can figure out how to do that.

I need to correct and clarify some sloppy/wrong wording on my original post. The #12 AWG blue hot line from the 20A GFCI breaker is the only lead that causes the breaker to trip. If that lead is connected to its terminal on the terminal block, the 20A breaker will trip. The other hot lead (red) from the 20A breaker can be connected or disconnected and it doesn't affect the breaker; the breaker always trips instantly if the blue lead is connected. It's been a few days now and I can't remember if I actually lifted the neutral to see if the breaker would stay in so I'm going to retest things this evening to see if the breaker stays in with either the neutral or the ground connected. So, I may have misspoken when I called this hot-to-ground short, it might be a hot-to-neutral ground fault; I'll make sure which it is tonight and post the results. Also, the 30A breaker does not trip, regardless of what's connected from the 20A breaker, unless I press its test button. The 20A breaker feeds the heater and the 30A breaker feeds pumps, light, etc.

I suppose if all else fails, I'll remove the new heater relay board and try to trace for continuity through the copper tracings that connect the blue lead to everything on the board. That will be a booger to do, though, and since the breaker still tripped when the repair tech installed another new board, I'm not sure how useful it would be.

Thanks for your help.

Orville Cypret

Here's the picture you asked about

I'm not at work so I can't check but I believe the #12's should be on terminals 1 and 3 and the #10's should be on 2, 4, and neutral on 5.

What does it say on the back of your control box cover?

You are correct: 20A blue-->terminal 1, 20A red--> terminal 3; 30A blue-->terminal 2, 30A red-->terminal 4, neutral-->terminal 5.

Last night, I connected the 20A hot legs to the terminals that would normally have the 30A service and moved the 30A hot legs to the 20A connection points. Both breakers stayed energized. Could the problem be a damaged 20A GFI resulting from the original problem of a relay shorting out on the board? I haven't checked to see if the damaged relay was fed by the 20A GFI.

I then restored the leads to the normal connection points. The 20A GFI again tripped. I removed the white neutral line from the 20A GFI and it stayed energized. That tells me the problem is some amount of leakage current escaping through a hot-to-neutral short on the 20A service.

As soon as I can this weekend, I'll check the resistance between the neutral and that particular hot leg from the 20A breaker and I'll remove the new heater relay board and check the resistance across those 2 terminals on the terminal block.

What risks do you see if I reverse the leads again, i.e., connect the 20A GFI leads to the points where the 30A GFI would normally connect and the 30A leads to the points where the 20A leads normally attach? Since, as I said above, the breakers both stay energized in that configuration, that would put the spa back in service. I'm considering rewiring it this way and leaving for the weekend to see what happens. The 20A service normally supplies power to the heater and the 30A GFI supplies power to the pumps. Since I don't have any reason to believe there is a problem with the heater, running the power through a 30A breaker instead of the 20A breaker doesn't seem to carry any danger with it. The only issue I can see is whether or not the pumps will run off a 20A circuit instead of their normal 30A service. By leaving it configured this way for the weekend to see if either of the breakers trip, I think I will get pretty firm indication if the tub components can operate with those amperages.

I suppose an alternative would be to replace the 2-pole 20A GFI & see if the breaker holds. If it does, that clinches the problem as a weak, overly sensitive 20A GFI probably damaged when the original short happened.

Orville