On Jan 29, 2:14*am, Tim Watts wrote:
On Tuesday 29 January 2013 00:14 Meanie wrote in alt.home.repair:
It's been a few weeks but just an FYI for those who helped me and are
interested in the outcome of the circuit which was out. It ended up
being a fried neutral behind my medicine cabinet. The medicine cavinet
hid a huge cutout in the wall. The wires were in the wall (not in a box)
exposed and TAPED, not wire nutted.
Oh dear... There's always some fool who should not be let near anything more
demanding than changing a torch bulb...
All neutrals were tied together as
were all blacks (3 each) then the wires ran through a hole in the wall
into the rear of the three lamp fixture above the cabinet and the rest
continuing the run. The romex wiring was old and brittle, but there was
corrosion and burning. The scary part is the thought of it catching fire
because you could clearly see the burn marks on part of the wall.
Can you get a full electrical test done?
Don't know what your standard offerings are here, but when I test (my own,
British system) wiring with a Megger, the principle standard tests a
0) Test the main incoming line (hot) to ground impedance.
1) Loop impedance (very low ohms) test done at low voltage on a dead system.
Eg with a radial socket (and maybe lighting) system such as you probably
have, we would remove the cable from the breaker in the panel, connect line
to neutral (or I suppose line to line, for one of your 220V circuits),
isolate or bridge any lighting dimmers and other electronics, remove all
loads plugged in and any lamps then go round all sockets and measure between
line and neutral.
Ditto at lamp holders.
Now bridge line to ground at the breaker and repeat. Then neutral to ground.
This is an incredibly sensitive test that would almost certainly show up
taped and loose joints. You can usually pin the fault down to a particular
patch of cable too.
Actual max values permitted depend on breaker value and tripping
characteristic (curve) protecting that circuit.
2) With everything still isolated, bridges removed, do a high voltage
resistance test (ours is done at 500V DC on 240V wiring, your system will
probably be done diferently) between L+N, N+E (ground) and L+E.
3) Recconnect and test the RCD/GFCI if fitted - again, needs a special meter
to test as we are looking for adequately fast disconnection times on both a
top side and bottom side (of the sine wave) trip as well as it operating at
the right leakage.
So in short, there's not a lot that gets by that testing regime even before
you open up sockets and switches for a visual inspection.
Cost - usually a couple of hundred pounds UK for a small/medium house (if
done right, it takes 1/2 a day to a full day).
I assume you would have something similar - perhaps someone can say what
it's called? Anyway, I'd get one done, unless you are planning to replace
all your wiring in short order.
It took awhile because I upgraded my service panel. When I learned it
wasn't in the panel, I went back to the search with my hunch to the
bathroom fixture since the main wire started from the panel to the
bathroom.
The more I remodel or repair, the more I learn whoever did these jobs
was an idiot.
--
Tim Watts * * * * * * * * Personal Blog:http://www.dionic..net/tim/
"History will be kind to me for I intend to write it."
What you describe sounds like it is absolutely correct. But, I have
never heard of a similar test protocol here in the USA. Maybe someone
can inform me if this is done here.