"John G" wrote in message

I'll save it for another thread but my neighbor's electrician son solved a
very interesting puzzle in which some of the lights in his mom's house
went
off for several hours early in the AM and then came back on by themselves
without resetting any breakers or GFCI's. I couldn't diagnose it, and
neither could he until I told him that a single UPS's started chirping at
3AM, which I thought was low voltage but seemed to be battery failure., so
I
got up and shut it off. No other UPSs beeped so I assumed it was a local
event until my neighbor told me about her basement tenant's lights going
out, too. When I restored power to the UPS and turned it back on the next
day, everything was fine and the battery tested out as good - I was about
to
replace it just in case but it was less than a year old.

You've got good analytical skills, John. What do you think it was? (-:


Loose connections at the power company transformer.

Bingo. When we compared what circuits had failed it was clear they were all
on one phase. A neighbor who's on the "critical service" program called
them when his CPAP (breathing device for sleep apnea) failed and they sent
out a truck ASAP.

See, I told you that you had good troubleshooting skills. (-:

This past week I got a call from a couple living in a condo who have been
having problems with their cable box going out briefly and then coming back
on. I was there a year ago for the same problem on one of their cable
boxes. This time it was all three boxes. They had the cable company come
out so many times to rewire and replace that they will no longer come out
for this problem which they believe is with the electrical wiring. Last
year I pigtailed and replaced 2 outlets and never heard back from the couple
until this week. Last year they reported that nothing else was occurring
such as flickering lights. This year it was the same, no flickering lights,
but they also admitted that they did not use the lights on these circuits
too often. I found the three cable boxes to be on two circuits. I checked
the voltage at the main panel and it was consistent on both phases and to
ground as well as to neutral. I replaced the two breakers and opened up
every switch and outlet on these circuits. The outlets were a builders
cheapo model with no screw terminals, only the back stab holes. Every
outlet that I removed from the wall had the wires come out of the back stab
with little effort. On one particular wall receptacle with six wires
attached, one of the neutral wires had only about a quarter inch of copper
showing which made me think that it was not making good contact when it was
inserted into the back of the original outlet. I pigtailed and replaced
every outlet on the two circuits. I tightened every connection in the main
panel. The only thing that I could not do was check the main breaker
because it was in a 6 gang meter stack that the power company had locked up.
I told the couple to call me if the problem persisted and I would get the
power company to unlock the meters.

They call them "backstabs" because IMHO, that's exactly what they'll do to
you. I became a hero to my wife (when we were still dating many moons ago)
by fixing a garbage disposal that was about to be replaced after her dad,
her handyman friend and even an electrician could not diagnose the problem.
A faulty back stab on the control switch (which was on an outside wall where
it got cold enough for thermal contraction to make it loose) turned out to
be the culprit. The clue was it happened more in the winter than in the
summer. The switch's backstab clips still gripped the wire - a little - but
they were very easily pulled out of the holes, which doesn't happen in a
good (if there is such a thing) backstab connection - at least not when they
are new. Just moving the wires out of the backstab holes and under the
screw fixed it. I did spend a lot of time upside under the sink before
deciding the problem lay elsewhere. (-:

A tool that I have found to be very helpful is the Amprobe Inspector:
http://www.amazon.com/gp/product/B00...7Y2DQQOIYSDVF7
On the above job it told me that I was on the right track by pigtailing when
I compared the before and after readings.

I recall seriously considering this tool before when I had a near fire from
a space heater plug that had become partially pulled out of the outlet. I
recall that it didn't detect arc faults and so I passed. Is that correct?
I seem to recall not many testers can detect potential arc fault situations
until they actually start arcing, but my memory isn't what it used to be.
It would be very useful, it sounds, in detecting old wires that have lost
some of their current carrying capability over time.

I was pretty sure I had that problem with old, cloth covered wiring that had
always had an oxide skin whenever I stripped it, but instead of trying to
test them, I just ran new outlets and took all the loads over 5A off the old
outlets. Doesn't mean someone won't plug in a space heater in one of those
old circuits some day so it might be worth almost $300 to know in advance if
that's going to be a threat. As I recall, a load like that might not trip
the breaker but could cause old wire with reduced capacity to start a fire
in the walls.

Another tool to use is an ammeter to measure the current on the grounding
electrode conductor at the water pipe and the ground rod. If there is
current flowing on the grounding electrode conductor, that tells you that
there is a problem with the neutral conductor.

This weekend I went to reach for my auto-ranging Wavetek A20 tong meter and
discovered the alkaline button batteries had leaked so much they destroyed
the damn thing. We can put a man on the moon, but are still plagued by
leaky alkaline technology. I the future I will make sure I use either
silver oxide or lithium button batteries if they are available in the size I
need. Really cheesed me off - it was a great meter with tongs just the
right size to fit into my circuit breaker panel.

It was invaluable in redistributing the loads in the panel and helped
uncover a 20A kitchen breaker that was happily allowing 23A to pass without
tripping. Gonna try a Harbor Freight cheapy (God help me!) just because I
rarely use it now. What really peeves me is that the batteries that leaked
(two LR-43's) were NOT cheap cells - they were Maxell's.

I should add that I was quite familiar with the condo complex above as I
have been doing work for the association for several years. In that time I
have found many problems that go back to the original installer.

I don't doubt that. The house my then future wife lived in had plenty of
"cheapest you can find builder specials" in it from the outlets to the
appliances. Guaranteed to last just long enough for the builder to pull up
stakes and move on.

One that stands out is a woman who had a new furnace installed in her
condo. She kept having problems with it and the service technician and her
own electrician told her it was an electrical service problem which was the
responsibility of the association. I measured 30 volts between ground and
neutral at her main panel. I go outside to have a look at the meter stack
and noticed a house panel for the outside lights. I took the cover off of
the house panel and saw a black wire on one main lug, a white wire on the
other main lug and a bare wire on the neutral bar. The house panel only had
one circuit breaker in it. I removed the stack cover and saw the black and
white on the main breaker and the bare on the ground terminal. I took the
white wire off the breaker and put it on the neutral bar. In the house
panel I took the white wire off the main lug and put it on the neutral bar.
I installed a separate ground bar and attached the bare wire to that as well
as the grounding conductor for the one circuit. The woman's furnace is now
working properly.

Well, I was right about you having not just good but excellent problem
solving skills. Before I learned to do my own work, I would have X-10
related problems that needed a licensed electrician. It became obvious to
me that some electricians can run new circuits and install A/Cs, furnaces,
etc. but really didn't have good troubleshooting skills.

My neighbor's son (who I first met when he was six years old and who used to
wash my car and mow my lawn to earn spending money) started as a cable
puller for the local CATV company. His boss soon realized he had much more
potential than that and sent him to school to become an electrician on his
own dime, an investment that's paid back handsomely. When people say that
today's kids are no damn good I just smile and don't even bother telling
them that I know better. His father ran out on the family when he was an
infant but he never used that as an excuse for bad behavior like his sisters
did. Instead he took his father's place and was the man of the house by the
time he was twelve, doing whatever he could to bring money in and to help
his mom around the house.

Very interesting thread, John. I'll have questions about that Amprobe. If
it's helpful to you, it HAS to be useful to a DIY guy like me.

--
Bobby G.