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Scary wiring found in fixtures

Hello all!

This is possibly more about general wiring practice than lighting, but I
thought it would be appreciated here.

A couple of weekends ago, I was over at a friend's place and we were in
his workshop. One room in the shop has a suspended ceiling with four
US-standard 4'x2' fluorescent fixtures, each with 4 4' T12 lamps, in it.
I'd been in the shop many times before and there were only two lamps in
each fixture. A month or so ago one of the fixtures was dark and I just
figured it needed new lamps. This time, that fixture was still dark, and
another one had two tubes that were lit along their full length, but not
very brightly - one side of the room was quite dim. I asked him if he'd
tried some new lamps and he said he had. The dark fixture he couldn't get
to work at all, unless he slammed a nearby door - then it would flash on
for a few seconds. The dim fixture did something interesting: when he
installed the lamps, some of them glowed very brightly at their ends for
a few seconds, then burned out. The ones that worked only glowed dimly.
He said that he had someone replace the ballasts in the fixtures a few
years ago, and thought they might need ballasts again. I offered to take
a look.

I figured the first fixture - the one that only worked when the door was
slammed - probably had a loose wire nut or lamp socket (aka "tombstone").
First I looked at the sockets and they looked OK and seemed to have plenty
of spring force when I installed the tubes. So I took down the center
metal channel to look at the wiring. One wire nut didn't seem very tight,
so I took it off, cut and re-stripped the wires and tried to reinstall
the wire nut. I noticed that when I got the wire nut on far enough that
it was starting to twist the insulated parts of the wires around one
another, one of the wires was tearing out of its insulation! Further
inspection revealed that several of the wires in this fixture had the
same insulation - it felt sticky on the outside and looked like a thick,
papery material on the inside - and it was just about to fall off of the
wires. Some of the wires had more normal THHN insulation and were fine.
The ballasts looked like they probably weren't original to the fixture,
but weren't brand new, either.

The second fixture was even more interesting. Only the center two lamps
were lit, but dimly. I tried installing a new lamp in one of the outer
positions and saw the same thing my friend did - a very bright flash from
one filament, followed by darkness, followed by the sound of filament
pieces rattling around when the lamp was then removed. I didn't have to
take down the center metal channel to look at the wiring on this one as
it had been helpfully left out by the last person who worked on it. I
started to trace out the wiring, didn't believe what I saw, and did it
again.

These fixtures are basically two two-lamp fixtures in a common housing.
There are two ballasts that each operate two lamps. The only place the
ballasts are *supposed* to be connected together is at the line
connections, so both of them can get power. Whoever wired it before
apparently didn't understand this, and had wired the *secondary* (lamp
side) of the ballasts together as well! The wiring diagram, as clearly
printed on the ballast label, called for:

I=========I
L-Bk-I I-R----.
N-W--I I-R---.|
I Ballast I ||
..--Y-I I-B-. ||
| .Y-I I-B.| ||
| | I=========I || ||
| | || ||
| +-#############-'| ||
| | # Lamp # | ||
+---#############--' ||
| | ||
| '-#############----'|
| # Lamp # |
'---#############-----'

In other words, the yellow wires go to one end of both lamps, while the
red wires go to the other end of the first lamp and the blue wires go to
the other end of the second lamp. The black and white wires are the line
(mains) connection. The way this fixture was wired, the yellow wires
from both ballasts were connected TOGETHER and to one end of two of the
lamps. I didn't trace further once I found that; I tore it all out and
started over. My guess was that the two ballasts were "fighting" to some
extent and that it worked until one of the ballasts "gave up". This
fixture also had wire with bad insulation. One redeeming feature of this
one was that it did have two relatively new ballasts in it.

So, I totally rewired both fixtures. My friend said it was OK to only
have two lamps per fixture, so I had plenty of good THHN wire and
tombstones to do it with. He claimed he had a couple of new-in-box
ballasts around the shop, but a search for them proved fruitless - I
did find the center channel for the second fixture, though. So, I had
four ballasts but only needed two. The first one I picked happened to
be good, so I got one fixture up and running. Of course, the next two
I picked were bad, so the second fixture didn't work until I tried all
three ballasts in it. (Is there some kind of industry standard single
connector system for ballasts? It would save a hell of a lot of time.)
I ended up with two bad ballasts - one older one and one newer one - and
lots of wire with bad insulation. I cut the wires off of the bad
ballasts right at the housing, and tossed the ballasts and the wire in
the trash in a location where they are unlikely to be "rescued" and
come back to haunt me. (Yes, both ballasts had "non PCB" stickers on
them.) I also ended up with some spare tombstones, which may come in
handy later.

The other two fixtures in that room seem to be working and I am going
to use the "if it ain't broke, don't fix it" philosophy for now. I've
never been in the military but one adage I have heard from military
types is "never volunteer for anything" - I am starting to think that
this may be a wise philosophy in general. I still kind of wonder how
someone can screw up the wiring when the diagram is printed right there
on the ballast.

Oh well, at least now the room is well lit. Plus, since I made sure
that he saw all the wires hanging down from the fixtures and the big
tangled pile of parts on the floor, I can probably still get a few
more beers out of him. :)

Have any of you found scary things in fixtures? I get the impression
that many of you work on commercial installations, where the wiring is
always done by trained, qualified, and licensed professionals, so
perhaps the really scary cases are only seen in residential work. Or
not.

Matt Roberds
 
T

TKM

Jan 1, 1970
0
Hello all!

This is possibly more about general wiring practice than lighting, but I
thought it would be appreciated here.

Have any of you found scary things in fixtures? I get the impression
that many of you work on commercial installations, where the wiring is
always done by trained, qualified, and licensed professionals, so
perhaps the really scary cases are only seen in residential work. Or
not.

Matt Roberds

Lots of scary electrical stuff out there. My worst did not involve a
lighting fixture, but rather the wiring in the house of my manager at the
time. He wanted to add some electrical outlets in his living room, but
didn't want to pay to have the wiring properly installed. Instead he
stapled flexible lamp cord to the baseboard. That was bad enough, but he
decided to run only one wire to the "hot"side of the supply at the nearest
outlet and to get the return or "neutral" side of the line by attaching the
neutral outlet wires to a handy steam radiator. Of course it worked since
the neutral and ground were tied together at the main panel, but I kept
waiting for sparks and fire every time I was in that house. He was the sort
of person who believed "as long as it works, it's O.K.".

Terry McGowan
 
L

Laurence Taylor

Jan 1, 1970
0
TKM said:
Lots of scary electrical stuff out there. My worst did not involve a
lighting fixture, but rather the wiring in the house of my manager at the
time. He wanted to add some electrical outlets in his living room, but
didn't want to pay to have the wiring properly installed. Instead he
stapled flexible lamp cord to the baseboard. That was bad enough, but he
decided to run only one wire to the "hot"side of the supply at the nearest
outlet and to get the return or "neutral" side of the line by attaching the
neutral outlet wires to a handy steam radiator. Of course it worked since
the neutral and ground were tied together at the main panel, but I kept
waiting for sparks and fire every time I was in that house. He was the sort
of person who believed "as long as it works, it's O.K.".

He's lucky he didn't get electrocuted.

I once came across a situation where, due to a wiring burn-out, a
short had occurred between the live and earth lines in the ring main,
the true earth (underground conduit) becoming isolated.

Not actually dangerous, as the place was largely earth-free (concrete
floor wth nylon carpet). Except ...

The water heater in the toilet was electric, and had a metal outlet
pipe over the sink. The sink, of course, had pipes that went
underground. If someone had happened to be touching both at once ...
nasty.


--

rgds
LAurence

....MONEY TALKS ... but all mine ever says is GOODBYE!
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