While we're doing house wiring questions ...

Factual Questions
1

I thought I’d ask about a problem that I seem to have solved, but didn’t figure out.

One 15A circuit in my house was wired to two bedrooms (one of which is not in use, it’s our guest room), the crawl space lights (two 75W incandescents, almost never used), and an outlet in the crawl space entry. The bedroom that is in use is my son’s, and has a small refrigerator, a portable phone, a 13" TV, a VCR, a cable box, one 75W incandescent ceiling light, two incandescent floor lamps, and occasionally his portable computer. Into the outlet in the crawl space entry, I plugged a surge supressor strip, and into that I plugged two 8-port Ethernet hubs and a 5-port hub and a DSL modem. I don’t know what the total load was.

The wiring order was service box -> unused bedroom -> my son’s room -> crawl space light switch -> crawl space entry outlet. The crawl space light switch did not switch the outlet.

For six months or so, no problem. Over a period of about two months, on some mornings I would find the outlet in the crawl space entry (and, therefore, the hubs and modem) and the crawl space lights dead. Some of the outlets in my son’s room might also be dead (but he was usually asleep, so I didn’t go lumbering around in there much). I think that sometimes all the outlets in his room were dead and sometimes none of them were dead and sometimes some were dead, but I don’t remember for sure. The breaker had not tripped.

If I ran an extension cord from the unused bedroom (I think on the same circuit), I got power at the hubs. After a day or two, I would check and the crawl space entry outlet would be live. After I plugged the hubs back into that, I would get a few hours to a week or so of power, then it would go dead again.

The breaker never tripped. All the outlets were wired correctly (tested with a cheap 3-LED tester). I opened up all the outlets in my son’s room and the crawl space switch box and couldn’t find any loose connections or evidence of failure. I had failures after opening all those things, so I didn’t fix anything by opening things up. I replaced the last outlet in my son’s room (just before the crawl space light switch) with no effect.

Finally, I replaced the breaker with a double breaker (the breaker box was full; it’s an all-electric house) and ran a new circuit to just the crawl space lights and crawl space entry outlet. (I did it that way because it didn’t require any fishing; my wife hates the way I curse while fishing). Since then, no problems anywhere.

It was sorta like the electricity was being asked to go farther than it was able to … but that’s ridiculous. Any ideas on what could have cause it?

2

You must have had either a bad breaker or a bad connection at a receptacle. Did you use the outlet checker when the outlets were “dead”?

Maybe you had an intermittent break in the wire under the insulation. Were the wires connected to the outlets with the screw terminals (very good), or the push-in holes (not as good)? You could even have had a bad outlet.

You don’t have aluminum wiring, do you? That can cause all sorts of intermittent problems when used with outlets.

Arjuna34

3

I don’t recall checking the outlets with the checker while some were dead. A bad connection at a receptacle was my first guess, but I couldn’t find one and replacing the most likely receptacle made no difference and there’s been no problems in my son’s room after running the new circuit, so that argues against a bad connection or receptacle. Sometimes there were definitely live outlets on the circuit followed by dead outlets, so I doubt the breaker was bad. I think the connections are a mixture of screw-terminals and push-ins. All copper wiring.

4

It still sounds like a bad connection. My suspicion is the push-on wire terminals- I’ve seen them cause problems before. It could also have been a bad outlet, or a break in the wire inside the insulation (both pretty rare, but I’ve seen them happen).

Arjuna34

5

Did you actually reset the breaker or just look at it. A breaker switch can be tripped without looking like it is.

I’ve got a circuit where the breaker doesn’t like to stay on. I have to reset it several times whenever I run anything from its outlet before it will stay on. Weird.

If the breaker was good, then yeah, probably a loose wire that gets jiggled whenever your son jumps up and down.

6

Copper wire can cause problems if it is tightened up too much.

Non-electrical folk have this idea that you should wind down terminals till the threads are just about locked.
What happens of course is that the copper spreads away from the terminal and just gets thinner.Over some time the thinner part warms and cools and eventually fatigues away and breaks but you can hardly see it.If you put a high impedance voltage tester on the terminal it may well give what appears to be an acceptable reading.

The right way is to tighten the connections just a little bit more than nipped, say a quarter turn, and if you are paranoid maybe go back a few months later and put another quarter turn on just in case there has been any slight movement.

I had one with an isolater switch and it turned out to be a bit of broken plastic that had fallen inside, sometimes it was in the way and sometimes not - very frustrating when you are looking elsewhere for the fault.

Sometimes with these things you never actually find what is wrong but you get so fed up of it you replace most everything and all is well, after all it isn’t the part that cost the money, it’s the time so it’s better to look for the fastest solution.

7

assuming no GFI outlets that were tripped, I would guess that either you missed a poor connection or more likely have missed an entire electrical box somewhere. if that is the case that’s where the problem is.
and whats all this about not wanting to wake your son, if he was young I could understand, but if he has his own computer/phone and frige in his room, wake him up had have him help you find out whats going on, map out the outlets on the circuit
also the crawl space could be a switch somewhere

8

I reset it.

I could have woken my son, but I woudl have been gone by the time he was awake enough to be of any help.

I guess it is probably a loose connection that I missed. But I don’t know why there are no problems on the original circuit since I ran the new circuit.