The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
breaker meltdown
by sparky
Yesterday at 07:30 PM
230 or 345 kV transmission lines?
by Vlado
09/24/16 09:33 AM
Electrical mast flashing product
by ThomasWinfrey
09/22/16 12:14 AM
What estimating software do you recommend?
by sparky
09/21/16 07:20 PM
"Dry Run" Inspection goes awry
by HotLine1
09/20/16 07:39 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
HotLine1 13
sparky 10
sparky66wv 8
gfretwell 8
Vlado 6
Who's Online
1 registered (HotLine1), 259 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 2 1 2 >
Topic Options
Rate This Topic
#217486 - 08/17/16 03:29 PM Can't use 2p gfci breakers on multi-wire?
Trick440 Offline
Member

Registered: 08/15/05
Posts: 248
Loc: Waterford, MI, USA
In Michigan all receptacles within 6' of water require gfci protection. This includes dishwasher and disposal. I ran a multi-wire for those 2 circuits. I forgot about the GFCI requirement and failed inspection. I figured I'll just spend the $100 on a 2p15a gfci breaker and call it good. Well.... I failed again! err, darn it!

I called the inspector and he said gfci breakers don't work on multi-wire. Stating that there will be a different draw on each leg and it will trip. I told him ok I didn't know that, I will research that and correct the violation.

Is this correct?
_________________________
Shake n Bake

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#217489 - 08/17/16 06:31 PM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
ghost307 Offline
Member

Registered: 05/09/05
Posts: 876
Loc: Chicago Illinois USA
I agree with the AHJ.
2 pole GFI breakers are suitable for a 240V-1 phase load, but not for multiwire branch circuits.
_________________________
Ghost307

Top
#217490 - 08/17/16 07:37 PM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
I thought there were some 120/240 GFCIs. What do they use on spas? They typically have L/L and L/N loads.
You might also find out they have them but not for your panel. This is the time to talk to your supply house.
_________________________
Greg Fretwell

Top
#217491 - 08/17/16 07:50 PM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
Siemens lists this one and I also saw a C/H GFCB220.
Both say 120/240 implying they will deal with L/N loads.

https://w3.usa.siemens.com/powerdistribu...-01-032-033.pdf
_________________________
Greg Fretwell

Top
#217492 - 08/17/16 07:51 PM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
Siemens lists this one and I also saw a C/H GFCB220.
Both say 120/240 implying they will deal with L/N loads.

https://w3.usa.siemens.com/powerdistribu...-01-032-033.pdf
_________________________
Greg Fretwell

Top
#217499 - 08/18/16 06:29 PM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
Trick440 Offline
Member

Registered: 08/15/05
Posts: 248
Loc: Waterford, MI, USA
It's a Cutler Hammer GFTCB215 (use to be GFCB215), 120/240v.


Edited by Trick440 (08/18/16 06:32 PM)
_________________________
Shake n Bake

Top
#217500 - 08/18/16 06:49 PM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
Trick440 Offline
Member

Registered: 08/15/05
Posts: 248
Loc: Waterford, MI, USA
I did find this...
http://ecmweb.com/content/think-gfci

"GFCI receptacles can be used on multiwire circuits, but they must be wired such that the neutral on the load side of the GFCI is not shared by two ungrounded conductors. Failure to observe this requirement will result in a differential current any time a load served by an ungrounded conductor not connected to the GFCI is energized, immediately tripping the GFCI.

Note that multipole GFCI circuit breakers are available for use on multiwire circuits. The GFCI sensor mechanisms in these breakers operate on the same principle as the GFCI receptacle, except that the current from all ungrounded conductors and the neutral pass through the "adding machine." As in the case of the receptacles, the unit will trip when it detects unbalanced current over the 4mA to 6mA trip range."


Not sure if the breaker I used is a true multi-pole, the 120/240v seems like it is.


Edited by Trick440 (08/18/16 06:52 PM)
_________________________
Shake n Bake

Top
#217501 - 08/18/16 07:29 PM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
Trick440 Offline
Member

Registered: 08/15/05
Posts: 248
Loc: Waterford, MI, USA
_________________________
Shake n Bake

Top
#217503 - 08/20/16 12:41 AM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
I bet the breaker you have, works. You can always put in a couple receptacles and try it. See if it will hold a load on each side (one at a time) and see if both sides trip with the GFCI tester
_________________________
Greg Fretwell

Top
#217504 - 08/20/16 12:35 PM Re: Can't use 2p gfci breakers on multi-wire? [Re: Trick440]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5299
Loc: Blue Collar Country
I have not responded until now, as it's been a decade since I installed a 2-pole GFCI breaker.

I had a little confusion installing that one; what I thought was a 'ground wire' on the circuit really needed to be treated as neutral, and pass through the breaker. (The receptacle was a 3-prong style).

I'd venture that if the breaker has a neutral terminal, it can handle single-pole loads. The internals appear to 'do the math.'

The only 'joker' is that the breaker likely has only one neutral connection; you'll need to combine your circuit neutrals before they get to the breaker. A pigtail and wire nut will suffice.

Top
Page 1 of 2 1 2 >



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals