Split Phase + GFCI question

[mct75]

Looking at an appliance which needs 240/120 power and also mandates a GFCI. Usually GFCIs on 240v loads are handled by a breaker that has the GFCI logic in it. Planning on wiring up a 14-30 plug for it and adding a double pole GFCI breaker for it.

I just have a question. What keeps the breaker from tripping as soon as you send current down the neutral (a 120v load)? Would it not see that as an imbalance between the two hot conductors and trip?

 

[u3b3rg33k]

Looking at an appliance which needs 240/120 power and also mandates a GFCI. Usually GFCIs on 240v loads are handled by a breaker that has the GFCI logic in it. Planning on wiring up a 14-30 plug for it and adding a double pole GFCI breaker for it.

I just have a question. What keeps the breaker from tripping as soon as you send current down the neutral (a 120v load)? Would it not see that as an imbalance between the two hot conductors and trip?

it would, if the current transformer was only around the two hots and not the neutral.

 

[Innovate1]

The neutral has to be routed through the breaker so it senses current on both hots and the neutral. You are right that if only the two hots got through the GFCI breaker it won't work and shut off sensing the current imbalance in the two hots. I think they make GFCI breakers for only 230V loads without the neutral and ones for 230/115V with the neutral.

 

[exranger06]

If you were installing a regular non-GFCI breaker, you would connect only the hot leg(s) to the breaker, and the neutral wire would simply connect directly to the neutral bar in the panel. When you install a GFCI breaker, you do NOT connect the neutral directly to the neutral bar. The GFCI breaker will have another terminal on it, and that's where you connect the neutral wire instead. The breaker will have a white pigtail wire attached to it, and that pigtail connects to the neutral bar. This is true for both single pole and double pole breakers. So basically, the breaker knows how much current is going through the neutral and will act accordingly.

If you were using a GFCI breaker for a 240V-only load (no neutral), you would still need to hook up the pigtail from the breaker to the neutral bar, even if there's no neutral wire connecting to the breaker. This is because the GFCI circuitry in the breaker needs the pigtail hooked up to work properly.

And finally, AFCI breakers get hooked up the same way, just FYI.

 

[rjacobs]

220 GFCI breakers, at least the Eaton CH type I am forced to use for my hot tub, are like $100 a piece...

As was said, they have a neutral wire that comes out of the breaker to attach to the neutral bus bar.

 

[alfredeneuman]

I think they make GFCI breakers for only 230V loads without the neutral and ones for 230/115V with the neutral.

No they don't. A 2 pole GFI monitors the both hots and the neutral, and any imbalance larger than 4-6ma between the three will trip the breaker, be it a 240 or 120 load.
EDIT: 240V circuit is still 120V to Ground

 

[u3b3rg33k]

220 GFCI breakers, at least the Eaton CH type I am forced to use for my hot tub, are like $100 a piece...

As was said, they have a neutral wire that comes out of the breaker to attach to the neutral bus bar.

$100 sounds like a steal to not die in a hottub from a ground fault...

 

[exranger06]

I've found that you can get brand new breakers on eBay for MUCH cheaper than the big box stores and pretty much anywhere else. I recently bought an Eaton CH AFCI breaker that's usually over $70 and I only paid $17. And it was brand new, not used.

 

[kaffine]

I've found that you can get brand new breakers on eBay for MUCH cheaper than the big box stores and pretty much anywhere else. I recently bought an Eaton CH AFCI breaker that's usually over $70 and I only paid $17. And it was brand new, not used.

Yes but is it really a Eaton CH AFCI breaker or is a counterfeit item? Then again that question needs to be asked for any supplier anymore.

 

[Terry D]

I've found that you can get brand new breakers on eBay for MUCH cheaper than the big box stores and pretty much anywhere else. I recently bought an Eaton CH AFCI breaker that's usually over $70 and I only paid $17. And it was brand new, not used.

If your paying 70.00 for that arc fault breaker, they are taking you. But I will agree, I have bought some breakers cheaper on line than my supply house. And yes the are brand new, factory breakers in the package

 

[exranger06]

Yes but is it really a Eaton CH AFCI breaker or is a counterfeit item? Then again that question needs to be asked for any supplier anymore.

It came in the Eaton box with the instruction manual and certainly looks legit to me

 

[exranger06]

If your paying 70.00 for that arc fault breaker, they are taking you. But I will agree, I have bought some breakers cheaper on line than my supply house. And yes the are brand new, factory breakers in the package

My memory failed me. Home Depot currently lists that breaker for $54, not $70. Still a significant savings getting it from eBay.

 

[nsula_country]

When building our house, I bought all breakers from Miami Breaker. 2, 42 slot panels 3/4 full.

Much cheaper than supply houses for Eaton CH AFCI, GFCI. Did not use any point of use GFCI receptacles. If required a GFCI, the circuit got a GFCI breaker. With exception of outside receptacles.

http://www.miamibreaker.com/

CT

 

[MattT]

No they don't. A 2 pole GFI monitors the both hots and the neutral, and any imbalance larger than 4-6ma between the three will trip the breaker, be it a 240 or 120 load.

I'm 99% certain I've seen 240v only GFI breakers. Not recently though so maybe all the newer ones are 240/120?

 

[mm08822]

I'm 99% certain I've seen 240v only GFI breakers. Not recently though so maybe all the newer ones are 240/120?

I know Sq D used to make a 2p 60a 208/240v rated GFCI. It had no neutral connection. Somebody got a new hot tub and it needed a 4 wire ckt. Previous ht was only 3 wire (h,h,grd).

I can find footnote references to it now, but all the current 60A part#/specs are for 120/240v versions.

I'm guessing they phased them out as one part to mfr/distribute is easier than two.

All the others listed in 15 thru 50 are w/neutral connection.