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.



*The Amprobe Inspector does not have a specific display that says that there is an arc fault condition. However, after using it for a while and taking before and after readings I realized that it does identify the conditions that could lead to an arc fault. This is not an idiot proof tool. I had trouble understanding the readings initially until I did a lot of testing and noticed the differences from outlet to outlet and circuit to circuit. For a DIYer I would suggest that they spend the time and money to redo all of the connections on their outlets and switches instead of buying an expensive tool. Arcing is a result of loose connections and the load passing through them.

Thank you for the praise Bobby,

John G




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.