Originally Posted By: dbozek This post was automatically imported from our archived forum.
None…that I can see. However, sometimes wires are doubled to handle current that just one wire cannot handle. Still don’t see a reason for that one though.
– You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln
Originally Posted By: jmyers This post was automatically imported from our archived forum.
Dennis,
Maybe you could explain that one a little further. If they used the neutral for another hot, would that mean the neutral is missing? and using the ground wire as the neutral?
That is assuming they did not try to make a 240 volt circuit out of this setup.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
jmyers wrote:
That is assuming they did not try to make a 240 volt circuit out of this setup.
I think that just might be the case. Not only do ya have a double tap, but the white wire should be re-identified (black marker, etc.) so people know it's hot ... not so important at the panel, but important at the other end. I would suspect it's not re-identified at the other end either.
Just my 2-nickels
-- Robert O'Connor, PE
Eagle Engineering ?
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I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: dbozek This post was automatically imported from our archived forum.
In order to get 240 volts the wires would have to be on different phases or two different breakers. It is hard to say why they put two wires on one breaker like that. Robert is right though, that the white wire should be marked, especially on the other end.
Why would they double wires to handle more current?
It's done all the time. If you look at a piece of stranded wire, you see individual strands. The more strands the greater ampacity the wire can maintain. Same principle here. Add a wire and you can handle more current through the two wires than you can with just one single wire.
However, in this case....something is fishy. does not make any sense as to why they would do that.
-- You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln
Originally Posted By: kmcmahon This post was automatically imported from our archived forum.
We’re talking about a 15amp breaker. There should be now need to draw more current as the single wire can handle more amperage safely than the breaker would allow. The breaker would trip before the wire would fail.
Funny thing is, this was a 200amp panel with plenty of spare room in it for more breakers. I think it had 12 breakers in all.
Hell, I don't know the reason and probably never will.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
You should never see parallel conductors smaller than 1/0. If the wire is smaller than 1/0 it should be a single conductor sized to the breaker and load. 310.4
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Usually when ya see a white wire used for hot it’s on a 240V circuit with the black wire going to another breaker off the other service feeder wire (there is 240V between the two service feeders wires on a typical residential service).
Another problem with that setup, besides the double tap, is that shutting down only one breaker will leave one of the wires hot. 240V circuits must be on breakers that have a handle which will shut power to both wires with one throw.
"Dennis" is right that connecting both wires of a circuit to the same breaker doesn't get you 240V. I also think Kevin and Greg are right that it doesn't make sense that they are used as parallel conductors for more ampacity due to the breaker size.
I guess it's also possible that it's just for a 120V circuit, but not as likely. Where did the white wire go to, and was there a black wire going to the neutral bar? That wasn't mentioned (pretty obvious), but it's possible.
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
The installer will connect the <reidentified> white wire to the hot, usually a wirenut, it goes to the switch and back on the black. Then the wires presented to the fixture will be a black and a white so it is harder to screw that one up.
This still should not be happening in a panelboard, only a J box where the light fixture connects.