daisy chaining duplex GFI

Feb 13, 2015 9 Replies
D

I'm working on our master bath, wife wanted a second duplex outlet near the vanity. OK, a PITA but no problem.



My plan was to daisy chain off the existing GFI outlet, running romex from it to the desired location. Problem is, the existing outlet has two romex cables coming into it...one is standard 12/2 (plus ground) - call it "A" - which is attached to one side of the outlet. The other is 12/4 romex (with two ground wires), call it "B". One pair of black & white "B" wires go to the side of the duplex opposite "A"; they then are pigtailed to the second pair of black & white "B" wires.



I'm guessing that romex "A" is what is feeding the existing outlet and that the "B" wires go somewhere - I know not where - to feed whatever.



If I want the potential duplex to be GFI, I need to feed it from the outgoing side of the existing outlet, correct? And how can I tell for sure which romex - "A" or "B" is feeding the existing outlet?


Vote
Twitter Facebook LinkedIn
T

Hi, Can't you find a marking like LINE(your A side) and LOADB). Sounds like that one is already daisy chained to some other outlet. If you want to find which outlet is connected, trip it by pushing the test button, and find out which outlet lost power.

Vote
Twitter Facebook LinkedIn
G

Trip the breaker, remove the device and separate all of the wires, turn on the breaker and measure them to see which one is hot.

Vote
Twitter Facebook LinkedIn
H

Tony hit the nail on the head. Somewhere on the existing gfci body it has to say "line" and "load", Flashlight or other bright light should make it easily visible.

Vote
Twitter Facebook LinkedIn
P

Yep, it should be clearly marked.

IIRC the top side it line-in

Of course (with the breaker off) the wires could be removed from the outlet...then with the breaker on...confirm with a volt meter

Vote
Twitter Facebook LinkedIn
D

Thanks, folks. I'll take a closer look at the existing receptacle. Also, just after I hit "send" for the OP it dawned on me that I could just take off the wires, turn on the breaker and check. duh... :)

Vote
Twitter Facebook LinkedIn
C

Or trip the gfi and check with the GFI tripped you would only have power on the "line in" side.

Vote
Twitter Facebook LinkedIn
D

Even easier. Thanks.

Who says newsgroups aren't useful? :)

Vote
Twitter Facebook LinkedIn
T

Hi, Dumb questions will get dumb answers, LOL!

Vote
Twitter Facebook LinkedIn
S

Do not perform this test while in bath tub full of warm water.

- . Christopher A. Young learn more about Jesus .

formatting link
. .

Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required