I need urgent help with electrical in my basement. I have 6 recessed
lights controlled by 3-way switch. Power comes to fixture #1, then to
#2 then #3, then #4 and from #4 it goes to #5 and #6. Two days ago
halogen 65W bulb on fixture #4 burnt out and I replaced it. As soon as
I replaced it fixtures #4, #5 and #6 start to dim. I found that if in
the group of fixtures #4, #5 and #6 I remove all but one bulb it works
OK, if I put the second bulb in that group both lights dim, if I put
all three they dim even more. Fixtures #1, #2 ans #3 work OK regardless
of three others. I was advise that there may be a loose wire somewhere
in circuit. I opened up fixture #4 and fixture #3. Voltage at fixture
#3 is OK, 120V between hot and ground or neutral. However, at fixture
#4 voltage is 60 V between hot and neutral, 60 V between neutral and
ground and 120 V between hot and ground. What can be wrong with the
wire connecting #3 and #4? The wire is BX armored cable AWG12. And
what's the best and safest way to fix the problem? I would like not to
remove that wire since to do so I have to rip sheetrock in half of the
basement. However I can put another cable in parallel.
Check your neutral and all electrical connections especially at the switch
From your description there is more going on that what you describe. Me
If there is really only 3 wires, between the fixtures, hot, neutral and
ground. Then connections problems come to mind. If there are more wires than
just 3 then it is hard to say from here.
The saga continues. The problem seems to be in the neutral between #3
and #4. Either leaving 3 or entering 4. Such that a load is drawing the
neutral up from ground potential as I said before.
Who made the fixtures? Are they retro fitted or original? You should be
able to remove the trim rings and drop the cans down, as here for
This is typical of Junos that I've worked on.
You seem to be able to see the BX. Where are you seeing it? This seems
to imply that you have access to the junction boxes for each of the
recessed lights and can check the connections. You'll have to take the
wire nuts completely off and inspect the connections.
I opened up the ceiling around fixture #3 and #4 meaning I cut
sheetrock on celing to completely expose thefixture. All fixtures are
Halo 6" new construction recessed lights. I verified that neutral,
ground and hot wire nut connections at both #3 and #4 are OK. I
unscrewed all wire nuts and examined all connections, I do not see any
problems in them. I measured voltage at fixture #4 between floating
hanging wires when two bulbs in problem group are dimmed. Again, 120V
hot-ground, 60V hot - neutral, 60V neatral - ground. I can't understand
what can cause such behavor? What I see is something is wrong with the
BX wireconnecting #3 and #4. however I do not understand what exactly
wrong. If wire in cable is broken there should be no voltage, if there
is shortcut, the breaker would trip.
Check all the nutted wire splices above fixture 4. I think one of the
neutrals came open and somehow changed the parallel wiring to something such
that two bulbs are powered in series. You should have gone from 4 to 5 to 6
instead of trying to parallel the last two connections. It should have
worked anyway but it setup a situation in fixture 4 with more wires and more
opportunities for miswires. Afterall it was fixture 4 you fooled with that
started the problem. The bulb blowing was irrelevant. The problem happened
when you moved stuff around changing the bulb. It worked once so it was
correctly wired at one time. A short would blow a circuit breaker, an open
is much more likely anyway.
I did this - disconnected #5 and #6 from #4. I also unscrewed wire nuts
at #4 and just hag wires. So if wires are hung at #4 meaning there is
no load voltage is 120V between hot and neutral. However if I screw
just fixture #4 with #5 and #6 disconnected I have 100V hot-neutral and
20 V neutral - ground. I then thought may be something wrong with
fixture #4 and unscrewed it but connected #5 at #4. Some effect,
voltage seems to be divided between hot and neutral relative to ground
depending on load, more load more voltage between neutral and ground
and less voltage between hot and ground. note, that at any case and i
measured it voltage at #3 is 120 V hot -neutral or ground and there is
no voltage between neutral and ground as it is supposed to be. It seems
I have eliminated all objects except that BX cable between #3 and #4.
Of cause I can replace that cable but i still want to understand what
can cause such weird behavior to avoid it in the future.
Sasha, What you just did here was a load test of the circuit up to that
point. This proves that the problem is ahead of #4. If you do a similar
load test at #3 and it passes the test, the problem is between there
and #4. I would completely take the wire nuts off and remake all
connections. This is with the proper gage wire stripper and with new
wire nuts. I use a pliers to twist the leads together (clean and
shiney) as well as to twist on the wire nut. If after this it fails the
load test at #4 and passes at #3 pull out that run of BX out and
replace it! If you're curious why it failed you will have to perform an
autopsy on that piece of BX. Unwrapping all the armor or pulling all
the wire out of it and checking it all. You'll probably find a broken
conductor somewhere in that run. Most likely there's a bad junction
that you're not catching. usually a broken conductor leading into a
junction that was partially nicked through then failed.
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