What Did I Break? Electrical Problem.

General Questions
#1

Okay, so I screwed up very badly the other day. The bulb in my desk lamp burned out Thursday night and when I tried to replace it, the glass part of the bulb
separated from the part you screw in. I had to go to bed so I left it for later. I was dead tired Friday night when I realized I still hadn’t replaced the bulb and I needed to use the lamp. Without thinking about it, I took a pair of pliers and started to unscrew the bottom of the bulb. Everything turned white for a second. My knuckles were singed and I felt like someone had tapped my chest petty hard. That’s when I realized I had forgotten to unplug the lamp.

As I was sitting on my bed wondering where I left my brain, the power went out in the back half of the house. It came back on after a couple of minutes. I checked all of the circuit breakers and none of them had been tripped.

Tonight (Tuesday), the power in my part of the house keeps going off and coming back on again randomly. The lamp is not plugged in. I have checked and rechecked the circuit breakers. I have turned them all off and then on again. They are not warm to the touch. There is nothing smoking and no burning smell anywhere in the house. I’ll be gone all day Wednesday (Mom will be here) so I can’t really do anything else or get anyone out here to help me until Thursday.

What have I done?

#2

I’m tapped out.

Anything that you could have done should have happened immediately, and involved the circuit breaker. Perhaps the two events are unrealated.

On a different note, next time a bulb breaks like that, use a potato, cut in half, and* unplug* the lamp first.

This reminds me of a stupid stunt I pulled in the sixth grade. In my class, I was seated next to a power outlet. I had a mechanical pencil. For some reason (I’m sure it was a good one at the time) I stuck two of the leads from it into the outlet–one into the hot, one into the neutral. Next thing I knew, I was being yelled at for sitting in the middle of the floor.

#3

If you mean the power is going out on outlets connected to the same circuit as the lamp was, I’d suspect that there is a loose, or corroded connection somewhere that existed prior to your fireworks experiment, but was made more severe afterward.

Typically, outlets are ‘daisy-chained’, meaning they are all connected in series, so a bad connection at any upstream outlet would show up on the downstream ones. The bad news is that if this is the case, you need to fix it or have it fixed, as a loose connection can create a lot of heat, and is a fire hazard, while not actually tripping a breaker.

#4

No, electrical outlets are hooked up in parallel circuits. But I do agree that there is a loose connection somewhere that needs immediate attention.

#5

It is by no means universal that electrical outlets are hooked up in parallel. I’d definitely start with the plug the lamp was in (with the power off this time).

#6

hopefully you have learned to unplug devices before working on them.

you possibly have a loose wire (connection) in the circuits affected. a real potential hazard.

#7

electrical receptacles are wired in parallel when they occur sequentially (in series) in a circuit. there are two meanings to being ‘in series’, they don’t mean the same and can be confusing to some maybe only making sense in context.

#8

Most often power feeds to one outlet and from it to the next, and the next. You will have the incoming power connected to one set of terminals and the feed to the next connected another. The connections where the wires are pushed into the back of the outlet often cause problems. I would start at the outlet closes to the breaker box and clean up all the terminals.

#9

The answer has essentially been given, but here it is in more detail:

Obviously a short-circuit was created. Normally this trips the breaker, but it sounds like in this case there was a weak point, a corroded or nicked segment of copper, that burned through first. Now it is making only intermittent contact. It is possible that the reason the breaker didn’t trip first is that the breaker itself has gone out, or is under-sensitive, so you may need to replace that too.

The failure is probably on a terminal, on a receptacle or in the panel. Oftentimes people who aren’t good at stripping insulation nick the copper at the beginning of the strip. (If you’re really unlucky, on the other hand, it’s a damaged point in the cable between boxes, where somebody pounded a staple in too hard or ran a drywall screw into it, or some such.)

Depending on how the receptacles were wired, the fact that a whole circuit’s worth are apparently going out together may or may not be significant–if it is significant, it would suggest that the fault is nearer to the panel end than the lamp end, if not actually in the panel. However, amateurs do not belong in hot panels; don’t get in there unless you have a main disconnect in a separate enclosure in front of the panel. Do not open any electrical box unless you are certain that the breaker to that circuit is off, and that power to that circuit has been cut off by the operation of that breaker.

If you have not clearly understood any part of this post, call an electrician.

#10

Besides checking the actual connections to the outlets, you also need to check anywhere 2 wires have been spliced (check for twist on connectors). If the 2 wires weren’t twisted together first before the connector was put on and if the connector wasn’t screwed on properly, over time the heat/cold expansion cycle can cause those connections to loosen which would look very much like a short.

#11

that is a good point.

the fault you are referring to is called an open connection.

#12

Very true… though in this case there clearly was a short. If the same circumstances had arisen without Sodalite’s pliers inside a hot socket, I’d assign a higher probability to this.

In any event, if one is going to the trouble of opening the receptacle boxes, yes, splices should be checked and remade as necessary along with terminal connections.

#13

That is what I meant. There isn’t a single wire that has drops to each outlet. in 99% of the cases, there is a supply wire coming into an outlet, and then another wire leaving to go to the next outlet. While the overall circuit is parallel, they are wired with each outlet in series. A single fault anywhere in the loop is a problem.

#14

In addition:
The breaker or first GFCI outlet your other outlets are attached to, could be damaged because of the incident with the lamp.

#15

You may have blown the fuse for only one phase of your 3-phase household wiring.
Open the disconnect panel, it should look similar to this Test the 3 phases for continuity through their fuses and replace the one in question.

#16

I thought household wiring was two phase, based on 220v. :confused:

#17

Sorry, I used a misnomer, I’m not an electician. :smack:
Your household wiring is single phase.
There are 3 wires coming into your house 2 Hot at 120v and one Neutral which supply your 120v/240v service.
Check the two fuses on the hot leads, one of these is most likely blown and will cause the problems you describe.

#18

Ah, thanks. :slight_smile:

#19

There was a short but the heat flash from the surge may have been the last straw.

These types of problems are usually the hardest to find unless you can reliably reproduce it.

#20

only experienced and skilled people should open disconnects or circuit breaker/fuse boxes. there is not anything an unskilled person can check or do. any checking needed can be done elsewhere. there is deadly extremely accessible electricity inside.

a swing open cover to reset circuit breakers or replace fuses is OK for the home occupant to open.