GFCIs in series


Old 07-02-05, 08:56 PM
Visiting Guest
Posts: n/a
GFCIs in series

I have rewired my kitchen, with three circuits. One is dedicated to the dishwasher, one is for the rear wall, one is for the front. Both of these have gfci's wired in series, and they all work fine. That is, until I introduce the lighting to them. I have come to learn that gfci's hate a shared neutral, no pigtail splices are allowed or the gfci's trip. So long as the series is unbroken with a switch, all is well. If I splice in a line for my overhead lights (3 way switches) or a line for my recessed sink lights, the circuit fails. I tried running the additional load directly from the gfci without a pigtail, in the secondary ports on the gfci, to no avail. I wired the lighting circiuts after the gfcis, this also made no difference. The gfci can sense a change in the resisitance before or after it, and I am trapped! I thought about removing all the gfcis except the one at the head end, but regardless, I believe that it will sense the neutral spice no matter how far from the gfci it is.

I have dismantled the plant several times, the only successful circuit is one that has no common neutral. When I look online, I see gfcis wired with pigtails. But for some reason, I cannot do this.

What am I doing wrong? The common thread between the two circuits is the lighting circuits that pigtail into the gfci series. Take them out, and the series works. Must I run a new circuit in to prevent this, or is there a way to have both together? Does a series of gfcis create this condition?

Any help would be greatly appreciated!
Sponsored Links
Old 07-02-05, 09:13 PM
Speedy Petey's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2003
Posts: 2,455
What you are doing is putting lighting on a kitchen receptacle circuit. Big violation. Move the lighting to a non-GFI protected lighting circuit.

Also, for the receptacles, use a GFI device at the first box. Then from the load terminals of that GFI run to the other standard receptacles.

The DW does not require a GFI and one is not recommended.
Old 07-02-05, 09:38 PM
Visiting Guest
Posts: n/a

Safe to assume that no spliced neutral will work with gfcis? I was confused by the site that showed the way to run a line out of the gfci that didn't need protected, like a lighting circuit. In the illustration, they put another line in the second port of the gfcis line in end.

Is this something recommended?
Old 07-02-05, 10:11 PM
Speedy Petey's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2003
Posts: 2,455
If you pigtail to the line terminals the downstream receptacles will not be protected. TO protect down stream recptacles your must abserve line and load correctly. You cannot pigtail anything between line and load.
You can pigtail anything after the GFI.
Old 07-02-05, 10:24 PM
Visiting Guest
Posts: n/a
I appreciate your help!

So, if you have the source wired to the gfcis line port, and another run of 12/2 in the secondary line ports of the gfci, this is not protected. That could be a light circuit....except that the gfci does not like a pigtailed/shared neutral. Is this because the gfci senses a difference in resistance because of the splice?

Looks like I will be running a 4th circuit up from the basement just for the lighting!

Thanks again for your advice!
Old 07-02-05, 11:50 PM
Join Date: Oct 2004
Location: USA
Posts: 719
Look at the GFI, two screws will be labeled Line. the other two screws will be labeled Load.
The line feeds power to the GFI. white and black in.
The LOAD side feeds other plugs that will be protected by this first GFI. White and black out.
Old 07-03-05, 06:00 AM
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
When you use shared neutrals with a GFCI you must only use the line terminals of the GFCI unless everything after the GFCI is without a shared neutral.

GFCI do not sense resistance. They sense current imbalance, which is why they trip with a shared neutral

But forget your plan anyway. You cannot have the lights on this circuit. Wire the lights on a separate circuit.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes