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 14
sparky 10
sparky66wv 8
gfretwell 8
Vlado 6
Who's Online
0 registered (), 54 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#181371 - 10/05/08 07:37 PM Shared neutral and 2 GFI circuits
Grover Offline
Member

Registered: 01/19/05
Posts: 110
Loc: Sebago, ME, USA
Can I run 12/3 across a garage, overhead to a basement, and then use this shared neutral to feed 2 GFI proctected dircuits? Pigtail the neutral to go to each separate circuit - each having 2-3 outlets - unknown and variable loads - depending on homeowner.

Breaker will be a 2 pole 20 - yoked - common trip.

Each GFI will compare incoming - red or black - with neutral, and will be independant of the load on the other red or black feed. Right?

So if the load on the black is 6A and the load on the red is 10A what happens? In this case, does the GFI device look only "downstream", or does it look "upstream" as well - that is, does it see the imbalance at the pigtail, or only on the load side of the device?

Or do I need a 2 pole GFI breaker?

Thanks!

Grov

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....

#181373 - 10/05/08 09:22 PM Re: Shared neutral and 2 GFI circuits [Re: Grover]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
A gfci does not look at anything on the line side of the device. As long as you split out your multiwire before you feed the GFCIs you will be fine
_________________________
Greg Fretwell

Top
#181378 - 10/06/08 04:18 AM Re: Shared neutral and 2 GFI circuits [Re: gfretwell]
wire_twister Offline
Member

Registered: 07/25/07
Posts: 265
Loc: Georgia USA
2 pole GFCI breaker will not work in that application, stick with the receptacles they will work for you.
_________________________
Jimmy

Life is tough, Life is tougher when you are stupid

Top
#181379 - 10/06/08 04:56 AM Re: Shared neutral and 2 GFI circuits [Re: wire_twister]
Grover Offline
Member

Registered: 01/19/05
Posts: 110
Loc: Sebago, ME, USA
Thanks guys!

Grov

Top
#181380 - 10/06/08 06:24 AM Re: Shared neutral and 2 GFI circuits [Re: Grover]
JBD Offline
Member

Registered: 07/12/01
Posts: 599
Loc: WI, USA
Actually, a 2-pole GFCI would work in your case, but there is no need to use one. Your GFCI receptacles idea is just fine.

GFCI's simply look at the total amount of current that flows out of their load terminals and compare it to the total amount that flows back in.

Top
#181475 - 10/11/08 02:51 AM Re: Shared neutral and 2 GFI circuits [Re: JBD]
Texas_Ranger Offline
Member

Registered: 12/17/01
Posts: 2331
Loc: Vienna, Austria
After all your 120/240 3 wire feeder is just like what feeds your main panel, so what should be the problem?

Top



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