7

I would appreciate any help or guidance. I'm in Canada and renovating what used to be the laundry room in my older house. I had originally planned on adding an outlet from one of the existing receptacles as part of the renovations. At the panel, a double pole 15 amp breaker with 14/3 wire is clearly labeled and dedicated to the room in question. The panel was upgraded within the last 30 years or so by a professional electrician and there is modern wire running from all breakers.

The 14/3 from the panel ends at the first receptacle in the room, where it runs into the outlet box along with 14/2 wire from a light switch. The red hot wire from the 14/3 is connected directly to the receptacle line, and the black is pigtailed together with black from the 14/2 wire and doesn't connect to this receptacle at all. The white neutrals are pigtailed together, and then feed into the appropriate line on the receptacle. This receptacle was used for a washing machine when the wiring was upgraded, and this is the only reason I can think of why maybe a separate hot wire was reserved for use here?

There are 3 other receptacles currently in this room as well, they are all wired as follows: They each have two separate runs of older NMD-3 12/2 wire that come down from the ceiling (currently hidden by drywall) and run parallel down stud bay into each outlet box. The hots and neutrals are pigtailed together, then connect to the lines on the receptacle. There are no wires connected to the load side of any of the plugs.

I'm familiar with running 12/2 and 14/2 to outlets and thought I had a basic understanding of typical wiring but what I've encountered here has me confused and intrigued. My first thought is that this was a type of multiwire branch circuit but it doesn't seem to fit with what I've read on those either. Is the double pole breaker being used to serve the room lights+plugs and also the washer plug as 2 separate 120v circuits? Why would 14/3 and a double breaker be used instead of just 14/2 and single pole breakers? Why the two runs of 12/2 into the other receptacles? Can I safely use 14/2 to add another outlet from the unused load side of the first plug that previously served the washer?

Thanks again for any help or clarification you can provide.

First Receptacle / Washer Plug

Other plugs

3
  • I would say no based on the NEC the laundry circuit is currently required to be a dedicated 20 amp, my answer looks to be not liked but our code is similar and adding onto this would violate current code , if not a laundry circuit I would say it’s ok.
    – Ed Beal
    Commented Apr 26, 2020 at 15:44
  • Note that the question states "used to be the laundry room"
    – Ecnerwal
    Commented Apr 26, 2020 at 16:36
  • Then as I said it would be ok , maybe I missed that. But I did mention it was a mwbc and if not a laundry circuit it would be ok
    – Ed Beal
    Commented Apr 27, 2020 at 2:25

4 Answers 4

6

Well it IS a MWBC. It just happens to be one that serves one outlet on the one side, and (presumably you've checked that the other outlets do actually turn off when the breaker does) the remainder of the outlets and the lights from the other half. It still economizes the wire from the panel to the room (one 14/3 rather than 2 14/2's.)

The older 12Ga wire presumably just means that the older outlet wiring that was not changed out was done with 12/2, and might have been on a 20A circuit at that time. Since it's more than large enough for 15A, that's perfectly safe in the current arrangement. Likely the two runs of wire are in, and on to the next device in the chain.

Personally, I find the combining of outlets and lights to be a thing I object to (since I don't like getting left in the dark, and fixed lights almost never trip a circuit breaker, while outlets get whatever plugged into them until they do) but electrical codes in both of our countries don't care about that.

4

Yes, it's straightforward enough and normal for MWBCs.

Your MWBC is coming in with dual 15A sub-circuits. The "Red" sub-circuit peels off and serves this receptacle, which I gather is the washing machine. The "Black" sub-circuit continues "onward" to parts unknown.

Beyond this point, the black+white behave just like a normal non-MWBC. So if you are expert enough with GFCI that you can competently use the LOAD screws to GFCI-protect a downline circuit, you are welcome to go ahead and do that. (you can't do that where the MWBC carries both hots onward, but you can do it on the rest of this circuit).

Where does it go? Easy. Since you know the red goes only here, go ahead and shut off the breaker and see what else loses power.

2

I am not sure of Canada’s requirements, in the US today a dedicated 20 amp circuit is required for the laundry branch circuit. You have a multiwire branch circuit the pigtails on the neutral are normally a requirement incase the receptacle or light switch was removed the neutral can be lost if going through the screws. If your code allows the hot neutral and ground to be extended I would see no problem with that but would verify that your code has not been updated to require a 20 amp dedicated circuit as I think our requirements are very similar and if so you could probably not extend that circuit.

0

The "other" outlets, the ones with two 12/2 each, may well be daisy-chained off each other, with the cables running from one joist bay to the next above the ceiling.

As for why they did this with pigtails in the box, instead of using the load terminals on the outlets: that's the right way to do it. It's so that if an outlet is removed (or if one of the connections to it loosens) current from the downstream outlets isn't interrupted. In fact Canadian code prohibits using outlet terminals for downstream neutrals, to avoid an open neutral on a hot outlet. The second terminal on the neutral side is only for if you've split the receptacle.

I think the two 12/2 should not both be entering through the same cable clamp, as I believe we're seeing. It may depend on the exact kind of clamp.

I agree splitting a 14/3 for a light and a receptacle is not a great choice, but it sounds legal enough, providing the two lines are on opposite phases on tied breakers. (Also remember that in Canada, circuits with lighting fixtures can only ever be on 15A breakers, even if they're wired with 12 ga.)

As to whether your current renos are extensive enough to force an upgrade to the current code, I can't guess. I think I'd put my washer on one of the 12 ga lines.

Not sure what the StackExchange policy is about recommending books, but there's a series of books by a guy called P.S.Knight that cover electrical code for Canadian provinces. Used to be by province but now it looks like there's a multi-province one. At a glance it looks overpriced and a bit hokey, with hand-drawn pictures and a kinda cynical tone. But it's worth its weight in gold. Get the current one that applies to your province.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.