Spa Panel with GFI Wiring

I'm trying to wire up a 50A GFI spa sub panel to power my new brew kettle. I pulled a new 10/3 cable from my main panel to the sub panel. The main panel neutral and grounds are tied together. I connected the black and red from my main panel 2 pole breaker to the hot terminals in the new sub panel. The sub panel has a ground and neutral bus. Should I connect my white wire to the neutral bus and the ground to the ground bus in both panels which are also tied together in the main panel? The white neutral pigtail from the GFI will also need to go to the neutral bus. I tried this but the GFI breaker will trip as soon as you try to put it on with nothing connected to the load side. Any ideas on why this would be? The voltages are correct at the load side of the GFI. Should I not have connected my neutral and ground bus in the spa panel like I did? I'd appreciate any thoughts. I'm hoping this breaker isn't dead out of the box. I'd hate to have to take the panel down to return it. I'm going to assume I'm doing something incorrect first.

I'm not sure about what you are saying. The ONLY place in your system where the ground and neutral can be connected together is within the mains panel. If they are electrically connected in the sub panel, it will not work.

You say that you pulled a 10/3 cable from the mains panel to your sub. That is 3 wires. No? Where is the ground wire. It MUST be an independent line going to the sub.

More info please.

You need 4 wires for 220 (2 - Hot, Ground, Neutral). The 3 wire that you have is for 110, which is Hot, Neutral, Ground.

Have to remember that Neutral carries power, so from what I'm reading, you are grounding the neutral, if you tied the ground and neutral together.

Also, 10 gauge can't handle 50 amps.

I guess if you are running all 220, you could use 3 wire, like the old clothes driers, but you lose your neutral than.

You need 6/3 with ground if it's romex.

BEFORE YOU READ THIS KNOW THAT I AM JUST AN ELECTRICAL APPRENTICE I AM NOT A LICENCED ELECTRICIAN NOR CAN I GIVE YOU THE ADVICE OF AN ELECTRCICIAN, I RECOMEND THAT AFTER YOU THIS YOU AT LEAST ASK A LICENCED ELECTRICIAN WHAT HE OR SHE THINKS BEFORE YOU DO SOMETHING ELSE

Now I did not mean to come across as rude with the caps but electricity is serious business and I dont want someone to take my opinion for gospel and get hurt or killed, that being said I have a few thoughts on your dilemma.

GFCI breakers/panels can and will be finiky. Most GFCI equipment (plugs, breakers, ect) have to "see" a load on them before they will function. So basically if I understand what you have written correctly, you have tried to turn power on, just to see if it works and you dont see power with out a load. This does not mean you did anything wrong. You could try plugging in the kettle and putting power to it, if this is so it will function if not the GFCI should trip.

"The sub panel has a ground and neutral bus. Should I connect my white wire to the neutral bus and the ground to the ground bus in both panels which are also tied together in the main panel?" Yes you should this is in theroy how this should be set up.

"The sub panel has a ground and neutral bus" These should be separate in the spa panel (as opposed to connected like in the main panel) and, What I am wondering is that your spa panel may need a separate and independant ground in order to function correctly ( GFCI plugs GFCI Panels and Breakers have internal electronics that "tell" them how to function, with out "seeing" the proper grounding your GFCI panel may not be working correctly)Now Im sure you have reviewed the literature that came with your panel, look it over again, see if it specifies the need of an independant ground. Running one is fairly simple, you run a wire (no6 or larger from the ground lug on the sub panel outside to a ground rod (an 8 ft copper coated zinc rod with a point at one end availible at home depot or lowes) driven MOST of the way into the ground(except the last 4 in or so) and connect the two with what is called an "acorn" ( its like a clamp) if you do this make sure you have bare copper and a good connection at the panel and at the ground rod.

I again aplogize for the caps I just wanted to make sure I made clear that the best solution is to ask a licenced electrician, but I also wanted to be as much help as I could considering I do have some limited experience with things like this.

kirscp is correct, no 10 is only rated for 40 amps, check your brew kettle for its ratings, if it specifies 50 amps you need to kick up to no 8, however a 3 wire no 8 will work as you will have 2 hot legs (red and black) a neutral (white) and a ground (bare) the ground is not counted in romex cable as it is not considered a current carrying conductor

Disclaimer: I'm not an electrician.

kirscp said:

I guess if you are running all 220, you could use 3 wire, like the old clothes driers, but you lose your neutral than.

Click to expand...

If it weren't a GFI panel you'd be correct, but I believe the GFI breaker in the spa panel needs the neutral either way.

I'm looking at the instructions for my spa panel. The breaker in the spa panel does have a neutral tied to the neutral bus in the spa panel.

So, you need 4 wires from your main house panel to the spa panel: two hots (red/black), one neutral (white) and one ground (green/bare). The two hots go to either side of the breaker in the spa panel (or the main disconnect in the spa panel, which is wired to either side of the breaker).

The neutral goes to the neutral bus, which should also have the pigtail from the breaker tied to it. And the ground goes to the ground bus.

Then if you want 220v to your elements, you take the two hots and a ground.

If you want 110v for your pump, you take one hot (either one), a neutral and a ground.

Don't forget, if you're taking off for a pump or any lower amperage loads you'll need an appropriately sized breaker downstream to protect the lighter gauge wire.

-Joe

I appreciate the replies. It sounds like what I thought was correct and what I tried will not work. I'll clean up my ground in the sub panel to my ground rod outside. The breaker in my main is 30A so I'm good with the #10 wire. I only need 30A but the spa 50A GFI was an easy GFI vs a $100 30A GFI individual breaker. This should be fine to code as far as my understanding goes. The 10/3 is 3 conductors with a bare ground. I guess I wasn't clear there. I thought I could get by testing this stuff out by going from ground in my main panel to ground in my sub and neutral in my main to neutral in my sub. This I guess is making a ground loop?

I've had a licensed electrician review what my ultimate plans are but I really just wanted to test the breaker to make sure it worked. I'm not used to GFI breakers, just the receptacles.

I double checked the spa panel wiring diagram and made sure I had everything right. I can't see anything that isn't correct. The breaker still trips as soon as you put power on it. I still am trying this with no wires on the load side except the pigtail tied to the neutral bus.

I decided to pull the breaker out of the panel and put it in my main panel to rule out anything I'm doing in the panel or in my wiring. The sub panel is just 1 foot away from my main if it makes any difference though. When I put the GFI breaker in my main and tie the pig tail to the neutral bus it still trips as soon as you put power on it with no wires on the load side. Is this normal? It just doesn't seem like it would require a load to work. If it did, would it not just trip as soon as the SSR turns off the heater?

What could I be missing? I seem to fair better working 2300V and up protection systems....At least I can talk to those protective devices. This GFI is throwing me for a loop.

I believe the GFCI breaker is defective based on your description.

Turns out the breaker was bad. I returned it and got a new one today and have no issues.

Thanks for the help! I've cleaned up the installation based on your comments.

Excellent news. Thanks very much for the update.