Mixing of Wires Question

starrapido said:

Hi,

I presently have a circuit that is connected to a 15A circuit breaker at main box. The wire on this circuit is 12-2, but then goes outside to a few GFCI's and outdoor lights and this wire is 14-2. Is that ok or should I be worried. I have tested all the GFI's and they are grounded and the trip works on them.

Thanks, I am not a skilled electrician just learning about DIY amd home improvement.

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We always sized the circuit by the smallest conductor as you posted there so therefore you have 14-2 that is good for 15 amp circuits only but you also have 12-2 there as well that can be used either 15 or 20 amp circuit however as you have other conductor size you are restricted to the smaller conductors if there.

If you really want 20 amp circuit then you will have to run a new cable or conductors if in the conduit.

Merci,
Marc

frenchelectrican said:

We always sized the circuit by the smallest conductor as you posted there so therefore you have 14-2 that is good for 15 amp circuits only but you also have 12-2 there as well that can be used either 15 or 20 amp circuit however as you have other conductor size you are restricted to the smaller conductors if there.

If you really want 20 amp circuit then you will have to run a new cable or conductors if in the conduit.

Merci,
Marc

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I totally agree. I would mark rhe 12-2 in panel with ""15 amp circuit only"

NJMarine said:

I totally agree. I would mark rhe 12-2 in panel with ""15 amp circuit only"

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Not code required, but I totally agree. This is what I do when I find this situation.

Thanks Frenchelectrician and NJMarine. So if I mark the panel with 15a circuit only that will work and can I assume that the set up with mixed wires should be ok ie: safe etc..

starrapido said:

Thanks Frenchelectrician and NJMarine. So if I mark the panel with 15a circuit only that will work and can I assume that the set up with mixed wires should be ok ie: safe etc..

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Did not realize SpeedyPetehad also responded - Thanks.

Thanks Frenchelectrician, SpeedyPetey and NJMarine. So if I mark the panel with 15a circuit only that will work and can I assume that the set up with mixed wires should be ok ie: safe etc.. ???

Yes, all ok and safe, even good workmanship in some situations. Two other things you might check. If you test trip one GFCI receptacle and other GFCI receptacles in the circuit go dead, that's poor workmanship. Also, any outdoor 14/2 should be labeled UF. If it's labeled NM, that's just wrong.

Thanks Glennsparky. Yes I have tested each of the GFI's they all trip and the others still work. I will try and check to see if the cable is marked UF or NM. It is inside the conduit though. If it is not UF then would that pose a risk at all?? Or would it not be safe even with all the GFI's working properly.?? Thanks.

Just checked and it was hard to see as the wire is in conduit. However in one of the GFI boxes it looked like the covering on the wire was white, so is that NM?? If so and it is not UF then would that pose a risk at all?? Or would it not be safe even with all the GFI's working properly.?? Thanks.

starrapido said:

Just checked and it was hard to see as the wire is in conduit. However in one of the GFI boxes it looked like the covering on the wire was white, so is that NM?? If so and it is not UF then would that pose a risk at all?? Or would it not be safe even with all the GFI's working properly.?? Thanks.

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If that came right out of the building it may be ok but as you say conduit ., If this part is outside then it have to be UF or THHN/THWN indivial conductors.

However most UF cable over the state side useally are in grey in colour but very few I know they can be white the only surefire way is by reading the info on the cable or look at one end the UF will be look much tougher to " skin " it off than the NM and NM will useally be much thinner and useally have a paper wrapped around ( sometime plastiquie or none depending on what manufacter it was used )

Really in fact you should use the UF cable or THHN/THWN conductors in the conduit for all the outdoor useage.

Merci,
Marc

I think it is NM as covering on the wire is white and looks like it had some brown paper on the inside, so is that NM?? If so then does this pose a risk at all?? Or would it not be safe even with all the GFI's working properly.?? Thanks.

Type NM would have a paper filler. Type UF is a solid covering around the conductors.

What you have needs to be removed if outside.

It is outside under a deck. We just moved in about six months ago and have not had any problems plus our neighbors tell us that it has been like that for years without issue. What are the risks of something going wrong if I just leave it as is with the wire in the conduit? All the GFI's work too.

If I do pull it all should I replace with the grey UF? and then would that be ok? Less risk? Would I need to put the UF back in the conduit? It is strapped to the decking joists underneath the deck. ie: they can't be damaged. Or try and bury the UF cable? Thanks.

starrapido said:

It is outside under a deck. We just moved in about six months ago and have not had any problems plus our neighbors tell us that it has been like that for years without issue. What are the risks of something going wrong if I just leave it as is with the wire in the conduit? All the GFI's work too.

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Did you say it's all in conduit? If so, and the conduit is continuous to all of the boxes, and the boxes themselves are proof against water entry, it should be OK. Cable inside conduit is unorthodox, but I don't know of any rule against it, as long as the conduit isn't over-filled.

fa_f3_20 said:

Did you say it's all in conduit? If so, and the conduit is continuous to all of the boxes, and the boxes themselves are proof against water entry, it should be OK. Cable inside conduit is unorthodox, but I don't know of any rule against it, as long as the conduit isn't over-filled.

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As long if this conduit is used outdoor then it have to be UF cable not the NM due the wet location and the condastion will build up inside the conduit that something you will have to think about it.

Merci,
Marc

Yes, it is all in conduit and all the joints have been cemented and also have weatherproof caulk around every joint. THe PVC conduit says 3/4" SCH 40 and so looks as though it has loads of room as only one 14/2 wire in it. Will condensation build up that much inside the conduit to cause a problem? Could I maybe drill a small hole at the lowest points of the conduit so if condensation does form it will be able to seep through small hole?