Well, I thought I had this issue figured out. But I guess it isn't so simple.
Spa-Repair/Spa-Parts/Recommendation-Marquis-Spa-Ozone-Replacement_5162.html

I replaced the ozone generator, installed it today, and the tub still trips as soon as the ozone comes on. I looked at the circuit board, and don't see any obvious signs of an issue (nothing burnt, loose, etc.)

If I unplug the ozone at the board, tub runs no problem. The ozone is 120V, but the service is 240V. Could it be a transformer that is the issue? I checked the wiring to the ozone twice, and I'm just not seeing anything.

The tub is a 2001 Marquis Coastal Reward. It was moved to where it is currently installed. The previous owner insisted there was no issue like this. I checked the tub out a couple of times before I had it moved, and I didn't see any signs of this. So, my suspicion is that something occurred when it was moved.

Suggestions on how to troubleshoot further?

Check your GFCI wiring with the instructions in this thread. Be sure your neutral line is isolated from ground all the way back to the main panel. 120v components have a way of exposing bad GFCI wiring in a 240v system.

That makes sense. The electrician who installed it seems like he wanted to just make it work and get out of there. I'll look at this more in a couple of days when I have time.

But, I have a question for the time being. I have a ground pin nearby left over from an old antenna I just removed. If I need a ground, that should fit the bill, right? If I ground the tub, do I need to ground the GFI? I'm asking the question, because, although I haven't looked at it with this in mind, I'm guessing that the electrician ran only 3 wires and bridged the ground and neutral. Does this make sense? Is this the kind of sloppy work that one might be likely to encounter? So, if he only ran 3 wires, and I need to add a ground, can I just ground the tub, and not worry about grounding the GFI? Then I can use the 3rd wire as the neutral. Make sense? Within code?

I checked it out, and the neutral and the ground are isolated all the way back to the main panel. But at the main panel, they appear to be on the same rail. From the diagram, this appears to be ok.

I checked the back plug of where the Ozone mini j-and-j plugs into. One wire (black) goes to the circuit board. The other (white) goes to the white (neutral)connector inside the spa system box.

Here is a quirk that may / may not affect this. One hot leg of the 240v is not on the jumper block that it looks like it "should" be on. This photo illustrates this. Could this be causing the issue? (BTW, that "red" connection is not on the green (neutral). There is an arrow that is obscured by the black wire that points to the green wire on the corner of that box.)

There are some situations where separating them at the main panel is not an option, but if it is, you should. I don't see anything obviously wrong in that picture.

Ok, so if I take the multimeter (electricity off) to the ground and the neutral at the hot tub (say, where that picture is taken) I should see no continuity, right? Or should I see continuity?

I can't separate them at the panel inside the house.

You'll have continuity between neutral and ground since they're tied together back at the main panel, which isn't uncommon.

Have you tried running the ozonator from a different terminal on the board, or even directly from one of the lines in? Is there anything between the ozonator and the board other than a plug or is there a ballast or transformer that was not replaced with the new ozonator?

No, I haven't tried that. From what I saw, there was just a plug for the ozone connector, and a white and a black wire leading from the back of it. I tried my best to trace those wires, it is very tight between there. The black wire goes to the circuit board. See attached file, it is pretty dark, but the others had too much flash.


The white wire from the back of the mini j-and-j plug is actually depicted in the previous post's photograph. It connects to the neutral (white).

I didn't see a transformer, and looked at the circuit diagram that is inside the box in the hot tub. Here's a shot of the whole board. Not sure if it will help, though.

Just wanted to double check on this. I can run the ozone from one of the legs of the pump power, correct? I would remove the black connector that goes from the ozone connector to the board, and put it on the board with one of the legs of the pump power, correct? I'm reluctant to just try this, considering the 120v ozone and 240v pumps. I don't want to burn anything out. by mixing voltages.

It would probably be better to run it directly from the incoming power or some other unused terminal. If you're going to do it from the pump leg, just disconnect the pump while you're running the ozonator. I don't think you'd do any damage, but just to be safe.