OT: Weird wiring
pyotr filipivich writes:
on Sun, 21 Mar 2021 20:22:06 -0400 typed in
rec.woodworking the following:
If you only turn off one breaker, you will often get some voltage that bleeds
back through the neutral at the supposed-to-be-dead fixture. If you used a
meter as opposed to a voltage sensor, I'll bet that it's not the full 120 VAC.
Now - although this is not something that I have ever seen - expand that to
a 4 wire source cable (3 hots and a single neutral) to the first junction box
and you've brought that 3rd breaker into the picture.
4-wire cable? It's used in dryer cables but it's a lot larger than
what you'd find in a lighting circuit.
Technically, 12-3 w/g is a 'four-wire cable' and along with 14-3 w/g
is used heavily in lighting circuits; to wit, in three and four-way
switched circuits.
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