UPB Wiring, no Neutral

[frijoli]

Guys help me here. This is a new one for me. I have a dual switch box. One switch controls my ceiling fan, the other controls the light kit in the fan.

Problem is, the three wires available have no neutral. The white is hot?? and connected to both switches. The black goes to the light through one switch, and the red goes to the fan through the other, but I have no return line in the box.

Is there anyway to fix this easily?

I can't imagine that getting past a real inspector!

Clay

 

[Steve]

It's 'Common' to wire a switch end of line like that. Usually the white wire will have black tape wrapped on it to show it is being used as a hot. The bottom line is you need a neutral in the box for UPB. How 'easy' it is to fix depends on how easy it is to run new wires in your house. If you can pull a new wire from the lamp to switch then it's easy. Just don't pull a neutral from another circuit whatever you do.

 

[PaulD]

The black goes to the light through one switch, and the red goes to the fan through the other, but I have no return line in the box.

Clay

Is the 3 wire white/black/red feeding the switch and then on to the fan & light? If so, the white should be your neutral while black and red are power.

 

[frijoli]

It's 'Common' to wire a switch end of line like that. Usually the white wire will have black tape wrapped on it to show it is being used as a hot. The bottom line is you need a neutral in the box for UPB. How 'easy' it is to fix depends on how easy it is to run new wires in your house. If you can pull a new wire from the lamp to switch then it's easy. Just don't pull a neutral from another circuit whatever you do.

Thanks, I won't pull a neutral from another circuit, but can you tell me why I shouldn't? I can't get the reason in my head.

Clay

 

[drozwood90]

Lets see,

At one point this is what I did...and it only really works on n-way and DUAL gang boxes.

for N-way, I used the traveler wire to bring the neutral to other boxes.

For Dual gang, where it is controlling a FAN and LIGHT on the SAME circuit...

I had two cables...each as 12-2 (Black, White, GND). IF the power will not overload a SINGLE wire...I re-wired my box, so that instead of there being 4 wires (1xfeeder and 1xswitched for each), I had 1xfeeder, 1xneutral, 2x switched. I have since moved, took all that out, and put things back to normal when I took out my automated switches, and just had a neutral provided in every box (best $100 upgrade I could have paid for!!). Just a side note, any changes you make...draw it out some way! It will make undoing anything like that SO MUCH easier...especially if you tag all the wires...then you can just monkey everything according to your drawing (wire A goes here, Wire B goes here). To put my stuff in...maybe 3 days per switch...as I had to figure out the wiring. TO take it out...1 day for the whole house (as I just had to follow the instructions I wrote...well for me!).

However, from your post, if you only have 3 wires...
red, white, black?

How are your switching 2 loads, with only 3 wires, if the neutral or hot are not in the box?

Is there HOT in the box? If you have HOT in the box, you can do what I suggested, just take one of the 3, make it a neutral (up at the fan) then you have everything you need in the box.

CMA: Do this at your own risk, make certain it's all the same circuit (do you don't accidentally make 220V in the box), loads, check your loading of the wires, <insert other stuff that I can't think of>, etc...etc...etc...

--Dan

 

[ano]

Here is what I would do. Use the black and white wires to run hot and neutral back from the light, so now your box has hot and neutral. Use the red from the switch to dim the light. So now you are missing a wire for the fan. Not a problem. Install another switch, but cap off the load. Then at the fan, install a UPB module (Model UFR) in the fan base to control the fan. Create a link in the switch and have it received by the UFR module.

If you don't have room for two switches, you can also use a Simply Automated split switch, having one side control the lamp (via the red wire) and the other side the fan (via a link).

Thanks, I won't pull a neutral from another circuit, but can you tell me why I shouldn't? I can't get the reason in my head.

1) Its against code.
2) It will trip any GFCI or AFCI on either circuit.

 

[Steve]

Thanks, I won't pull a neutral from another circuit, but can you tell me why I shouldn't? I can't get the reason in my head.

1) Its against code.
2) It will trip any GFCI or AFCI on either circuit.

Well, #1 is really the only reason needed but that will happen is that wire will be hot as a return path even when the circuit is off. Say to have circuit A with neutrals and circuit B with no neutral. You now take a neutral from circuit A and use it in circuit B. You now shut off circuit B to do some work but you will get in trouble because that circuit can still be energized via the neutral shared with circuit A. It can be a shocking (and dangerous) experience. Hope that makes some sense/

 

[ano]

Thanks, I won't pull a neutral from another circuit, but can you tell me why I shouldn't? I can't get the reason in my head.

1) Its against code.
2) It will trip any GFCI or AFCI on either circuit.

Well, #1 is really the only reason needed but that will happen is that wire will be hot as a return path even when the circuit is off. Say to have circuit A with neutrals and circuit B with no neutral. You now take a neutral from circuit A and use it in circuit B. You now shut off circuit B to do some work but you will get in trouble because that circuit can still be energized via the neutral shared with circuit A. It can be a shocking (and dangerous) experience. Hope that makes some sense/

Neutrals are not controlled by breakers, and they all tie back to the same point in your breaker box, which ties to ground. If a second leg which you took the neutral from has a high load on it, the neutral may become a few volts AC over ground but not more than that, assuming the neutral wire is not disconnected.

The big problem is wire overloading. Lets say you have two 15A circuits each with a 14A load. Under normal conditions, in each leg, you have 14A in the hot line and 14A in the neutral. But share a neutral, and you now have 14A on each hot line, but 28A on the one neutral, and since the neutral DOESN'T have a breaker, then you have a fire since the wire was designed to handle 15A, not 28A.

 

[frijoli]

Neutrals are not controlled by breakers, and they all tie back to the same point in your breaker box, which ties to ground. If a second leg which you took the neutral from has a high load on it, the neutral may become a few volts AC over ground but not more than that, assuming the neutral wire is not disconnected.

The big problem is wire overloading. Lets say you have two 15A circuits each with a 14A load. Under normal conditions, in each leg, you have 14A in the hot line and 14A in the neutral. But share a neutral, and you now have 14A on each hot line, but 28A on the one neutral, and since the neutral DOESN'T have a breaker, then you have a fire since the wire was designed to handle 15A, not 28A.

That's what I was trying to wrap my brain around!

Thanks,

Clay

 

[Steve]

That may be fine in theory, but I once had a situation I described earlier. There was a neutral pulled up from an outlet box that was below a switch box, obviously on a separate circuit. With the outlet circuit on and the switch circuit off, I got shocked when working on the switch circuit. And it was a 120V tingle, not some low voltage tingle.

 

[BraveSirRobbin]

That may be fine in theory, but I once had a situation I described earlier. There was a neutral pulled up from an outlet box that was below a switch box, obviously on a separate circuit. With the outlet circuit on and the switch circuit off, I got shocked when working on the switch circuit. And it was a 120V tingle, not some low voltage tingle.

Curious if this was near a 220 volt outlet Steve. I had a weird situation in my house where they 'shared' the neutral of a 120 volt outlet with a 220 volt outlet (or so the electrical company said). I had the breaker off to the 120 volt outlet and when I disconnected the neutral wire I had 120 volt between it and ground. Still can't wrap my head on how they got this all to pass code...

 

[Steve]

Nope, nowhere near 220

 

[drozwood90]

The big problem is wire overloading. Lets say you have two 15A circuits each with a 14A load. Under normal conditions, in each leg, you have 14A in the hot line and 14A in the neutral. But share a neutral, and you now have 14A on each hot line, but 28A on the one neutral, and since the neutral DOESN'T have a breaker, then you have a fire since the wire was designed to handle 15A, not 28A.

Agreed. The only time it is allowed, is if the lines are a split 220V. I.e. it's really a 220V circuit that has been split to two 120V lines. Then loading doesn't matter as the time when you will have the MOST load on the neutral is when only one circuit is energized. However, this is really only allowed in specific circumstances.

--Dan

 

[ano]

Nope, nowhere near 220

I think you might be talking about a shared neutral for two 120V circuits. This is a bit like a 220V circuit but different. I think a shared neutral IS actually allowed, but its highly discouraged, but some builders, to save money do it. The trick here is that BOTH circuits HAVE to controlled by two adjacent breakers with a connecting bar between them (NEC 2008), so they are either both on OR both off.

The trick here is that each is on an opposite phase, so, the neutral wire will never carry more current than either hot wire. In fact, if both hot wires carry the same load, the neutral doesn't carry ANY current.

Again this is technically legal, and you do see them on occasion, but I think its really a BAD idea to save a wire, and if not done correctly, as Steve says, it can be VERY dangerous.

The dual-breaker requirement is new as of the 2008 NEC, but may not be required in your state. Before that, the breakers didn't need to be adjacent, but they did need to be on opposite phases. While done in the past, you should follow NEC 2008 for future work.

 

[GT!]

That may be fine in theory, but I once had a situation I described earlier. There was a neutral pulled up from an outlet box that was below a switch box, obviously on a separate circuit. With the outlet circuit on and the switch circuit off, I got shocked when working on the switch circuit. And it was a 120V tingle, not some low voltage tingle.

Either it wasn't really a neutral or something else in your box was hot. As has been pointed out previously, neutrals are never switched at the breaker panel, so turning off a breaker will never change the state of a neutral wire - neutrals are always connected.

-GT