ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Recent Posts
What do you do?
by HotLine1. 10/16/17 07:22 PM
Good ol' copper pipe in the fuse holder trick
by HotLine1. 10/16/17 07:16 PM
Generator Cable Sizing
by HotLine1. 10/16/17 07:13 PM
Another generator question
by HotLine1. 10/16/17 07:02 PM
Thermal Imaging Camera upgrade
by SteveFehr. 10/15/17 08:15 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
241,326 Are you busy
177,273 Re: Forum
168,914 Need opinion
Who's Online Now
0 registered members (), 55 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#181371 - 10/05/08 10:37 PM Shared neutral and 2 GFI circuits  
Grover  Offline
Member
Joined: Jan 2005
Posts: 109
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


Work Gear for Electricians and the Trades

#181373 - 10/06/08 12:22 AM Re: Shared neutral and 2 GFI circuits [Re: Grover]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,120
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

#181378 - 10/06/08 07:18 AM Re: Shared neutral and 2 GFI circuits [Re: gfretwell]  
wire_twister  Offline
Member
Joined: Jul 2007
Posts: 265
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

#181379 - 10/06/08 07:56 AM Re: Shared neutral and 2 GFI circuits [Re: wire_twister]  
Grover  Offline
Member
Joined: Jan 2005
Posts: 109
Sebago, ME, USA
Thanks guys!

Grov


#181380 - 10/06/08 09:24 AM Re: Shared neutral and 2 GFI circuits [Re: Grover]  
JBD  Offline
Member
Joined: Jul 2001
Posts: 599
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.


#181475 - 10/11/08 05:51 AM Re: Shared neutral and 2 GFI circuits [Re: JBD]  
Texas_Ranger  Offline
Member
Joined: Dec 2001
Posts: 2,402
Vienna, Austria
After all your 120/240 3 wire feeder is just like what feeds your main panel, so what should be the problem?



Member Spotlight
mxslick
mxslick
Atomic City, ID USA
Posts: 803
Joined: October 2004
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.016s Queries: 15 (0.003s) Memory: 0.7775 MB (Peak: 0.9262 MB) Zlib enabled. Server Time: 2017-10-17 02:04:50 UTC