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wiring bathroom fixture with 4 separate switched items, need 5 conductors

wiring bathroom fixture with 4 separate switched items, need 5 conductors


  #1  
Old 01-27-18, 05:06 PM
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wiring bathroom fixture with 4 separate switched items, need 5 conductors

bathroom fixture has night light, light, fan, heater. currently not wired correctly. has 12-2 feeder, then a 12-2 from 1 switch carrying one hot and the neutral (1st switch leg) , 2 switches have one 12-2 with the white relabeled as hot (2nd and 3rd switched legs), and the last switch has a 12-2 using the hot but not using the neutral at all (4th switch leg). I'm pretty sure you can't have the hot and no neutral with it (as in 4th switch leg) or 2 hots and no neutral in 120v circuit (2nd and 3rd switch legs)

so I don't see any wire available with 5 conductors (4 hot and 1 neutral) I see 12-2-2 and 12-4, both having 4 conductors. conduit with individual conductors would work, but would require a new box with knockouts for the conduit which could be hard to get in. can I use 2 12-3 and tie the neutrals together at both ends would leave me 2 red and 2 black hots.

sorry I know this has been discussed and I may have even been involved but I couldn't find it?
 
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Old 01-27-18, 05:09 PM
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You can use two 12/3's and cap off one of the neutrals.
You don't have to use both of them.
 
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Old 01-27-18, 05:10 PM
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It is easier to use ENT and pull the conductors you need.
 
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Old 01-27-18, 05:22 PM
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wow, that was quick. The issue with using ENT may be difficult to put in new double gang box with knockout for ENT without tearing up the drywall. I will have to check. I don't have any wire for the individual pulls so would have to buy some rated for that-if I remember correctly the individual conductors in NM are not rated (or at least not labeled as being rated) as THHN/THWN?

Pjmax, thought you couldn't have two hots (same phase, not a 240 circuit) without a neutral running in same sheath?
 
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Old 01-27-18, 05:46 PM
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I don't believe that both neutrals need to be used.
If you use a piece of two wire cable for a switch loop there is no neutral.
 
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Old 01-27-18, 07:55 PM
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As long as it is NM cable and plastic boxes you don't have to worry about all being in same cable.
 
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Old 01-28-18, 07:33 AM
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yeh, understand switch loop, but I thought that was special situation. Are they even code anymore? I remember few years back they were very restricted, I think because a lot of the newer dimmers require a neutral.

So is the way I described my current setup actually up to code-excluding potential box fill issues?
 
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Old 01-28-18, 07:42 AM
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All the extra conductors may create a fill issue at the fixture.

Switch loops are still valid, but now would require a xx-3 cable.
 
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Old 01-28-18, 09:34 AM
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bathroom fixture has night light, light, fan, heater. currently not wired correctly. has 12-2 feeder, then a 12-2 from 1 switch carrying one hot and the neutral (1st switch leg) , 2 switches have one 12-2 with the white relabeled as hot (2nd and 3rd switched legs), and the last switch has a 12-2 using the hot but not using the neutral at all (4th switch leg). I'm pretty sure you can't have the hot and no neutral with it (as in 4th switch leg) or 2 hots and no neutral in 120v circuit (2nd and 3rd switch legs)
Fixture has one 12-2 feeder to bring in power.

... a 12-2 down to 1 switch carrying one hot and the neutral (1st switch leg) ...
What wire connects to the second switch terminal?

... last switch has a 12-2 from the fixture using the hot but not using the neutral at all (4th switch leg) ...
What wire connects to the second switch terminal?

To be an absolute purist you would have two 12-4 cables down from the fixture to the switch box. Cable A has hot down for switches 1 and 2, switched hot #1 up, switched hot #2 up, and neutral in case either of the preceding become a dimmer or timer. Cable B has hot down for switches 3 and 4, switched hot 3, switched hot 4, and neutral in case either of the preceding become a dimmer or timer. Neutrals are not tied together down in the switch box.

OT: There is a problem if power comes to the switch box and you have the usual two 12-xx cables to bring switched power 1, ... , switched power 4 to the fixture. You would have to break a rule:

1. Neutral not in same raceway as hot. One cable's neutral is connected to the fixture neutral and the other cable's neutral is capped off and all the switched hots connected to the respective fixture leads.

2. Combine neutrals downstream. Both cables' neutrals are connected to the single fixture neutral lead and all the switched hots connected to the respective fixture leads.
 

Last edited by AllanJ; 01-28-18 at 09:50 AM.
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Old 01-28-18, 09:37 AM
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You would jumper the one hot over for all the switches.
 
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Old 01-28-18, 10:44 AM
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AllanJ-the power is coming in to the switch box, not in to the fixture. and as pcboss says, there is just jumper to get power to both switches. there are 2 double switches in double gang box (hence potential for box fill issues), not 4 individual switches

So the rule about neutral not in same raceway I guess is what I was thinking about in above messages. That's why I was wondering if using the 2 12-3 as mentioned above was up to code. would using the neutral in one of the 12-3 and then not using it in the other violate this rule? is the sheathing considered a raceway?? But you are saying that you can't combine them either or violate rule 2? I don't understand about your scenario about bringing power to fixture first then down to switches. I guess making four switch loops? so you would have repurpose whites as hot. but don't see how you would have a neutral if need timer or timer in future? that would require another wire for each switch as pcboss mentions above needing xx-3 for (each) switch loop.

I'm guessing this isn't common to have 4 items in a fixture like this or they would make 12-5, LOL!

so conduit seems like most straightforward way to do it if doing to in new construction, but that is little harder in old construction.
 
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Old 01-28-18, 11:13 AM
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There is an exception for nonmetallic cables that could be used here. I would need to lookup the exact wording.
 
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Old 01-28-18, 07:47 PM
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I thought you said you had power arriving at the light. Others were talking about switch loops and switch loops apply only when power arrives at the light.

If there is an exception to not require neutral accompanying the hot then you can (I would go ahead and do it anyway) (with power arriving at the switch) use two 12-3 cables up to the fixture per reply #2 above. (The capped off white could in the future become a raw hot if you wanted to continue power from the fixture to additional outlet boxes.)
 

Last edited by AllanJ; 01-28-18 at 08:11 PM.
 

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