Too all who helped – thanks. I was the DIY who had a MBR ceiling light out. You responses allowed me to fix the problem with little effort. And from the responses I learned a little more about simple wiring issues in a house. If you want to know the solution read on if not – well thanks again.
I removed the receptacle and noted the ‘tabs’ on each side had been snipped. I put in a new one with the tabs intact and everything is fine. I obviously had cut the source for power off when I cut the tabs. So, the reasonable question might be, why cut the tab in the first place. To save my life!
Years ago when I was younger – less knowledgable – and with young children – I stayed up late on Christmas Eve to finish a paint job in the kitchen. Guests were to arrive early the next day. My then wife wanted everything perfect. When I was done painting I replaced every receptacle – make things look clean and neat. Each had two black and two white wires. Before this project I flipped the breakerS – caps are on purpose – for the kitchen. All was good. Beer in hand. Went down to reset the TWO breakers. When I reset one the other would flip. Remember I was stupider at the time. The only way I could get both to ‘hold’ was to set them carefully at the exact time. Now I felt good. Job done. Time for another beer. It was @ 3:00 am. I went to the kitchen to vacuum the small mess I had made. Remember all had to be perfect.
I plugged in the vacuum cleaner and turned the switch on. I cannot describe with words what happened next. The vacuum cleaner ran really fast – and smelled like fire. The receptacle blew out of the wall and a very beautiful – golf ball sized – glowing blue ball rolled across the floor. It hit the opposite wall and with a huge bang smoked my new paint job. Lots of really black soot. The hole where the receptacle once was was huge.
You guys know what I had done. Two lines to each duplex controlled by two seperate breakers. So after that I must have cut all tabs in fear of my life.
Problem solved and I am still alive.
Thanks again – Mike
Replies
My FIL did that once. He replaced the old, discoloured receptacles for new ones. One of them had the tabs removed and was on two different circuits. He replaced it with a new receptacle with the tabs intacts. He wondered why one breaker tripped everytime he flicked the other. Luckily he asked me what i thought the problem could be. No fireball in this case.
I really believe that if you don't know enough about electricity and need to ask a lot of questions, you shouldn't be playing with it in the first place.
How upset was dw with the damage to the paint?
"Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Forget the paint, what did she say about the huge hole where the outlet blew up/out?
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Phil: I put the cooler with the beer in front of the hole - not discovered until after Christmas. I may be stupid about electricty but I am not stupid. Mike
I'm trying to imagine the actual physics of connecting two different circuits to different halves of the same duplex outlet?If you were connecting breakers off the same side of the panel, I'm not seeing how that would be all that disastrous. But if you connected breakers from opposite sides of the panel... that alone seems like it would cause a short once you flipped the breakers, wouldn't it?It sounds like from the OP's description, he managed to connect two circuits to one duplex outlet and was able to turn both breakers on if he did them at the same time, but that there wasn't an issue until he plugged in the vacuum cleaner. What exactly happened?
Edited 4/14/2009 3:43 pm ET by geoffhazel
breakers that are adjacent to one another are going to read 220V regardless of what side of the panel they are on, the bus arrangement alternates on both sides of the panel.which is the reason for requiriing a tie handle when running a multi-wire circuit.however breakers that are opposite each other will be the same voltage, look at the panel cover and you may see the breakers on the left side numbered ODD
and the right side numbered EVEN#1 & #2 are opposite#1 & #3 are adjacent.
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Yeah, I hear what you are saying. I was thinking of it as "sides" being fed by the two hot leads coming in from the meter. You're right, they alternate with each other. What I was thinking was that if you have two circuits coming into an outlet box, you don't know if they are being fed from one "side" of the input voltage or the other side. If they were from opposite sides a meter across the hot leads would measure 220v, if from the same side, it would read 0 volts. Measuring either to ground would give 110v.
Eddie: We are divorced now. Something tells me her mother-in-law was actually that fireball that tried to kill me.
At least you knew who the guilty party was.
I have heard of case where people have gotten "new" receptacles from the home horror store and one of them will be one that some returned after then had cut a tab.
William the Geezer, the sequel to Billy the Kid - Shoe
Bill, can you explain to the rest of us exactly what must have happened?If OP wired two black wires from opposite phases to the two hot posts, then there would have been a closed 240V circuit through the tab with no load on it, which should have tripped one or both breakers immediately, shouldn't it?If he wired blacks from different phases to the hot and neutral posts on the outlet and whites to the other posts, it would have shorted out immediately through the tabs.The only way i know to burn up the vacuum cleaner would be opposite phase hots connected to hot and neutral sides of the outlet, but I don't see how that would blow up the receptacle.BruceT
I am not sure.The 240 on the vac would certain not help it. And it might short and draw enough current that the cord or plug could "explode".But I still don't see the kind of even that he described.And if the 2 hots where on the same leg there would not be any problem.If they where on oposite legs it would be a dead short and I don't see how he could ever have gotten the breakers closed.I am thinking that there was something else going at the same time.Maybe a bad connect where he made up the socket..
William the Geezer, the sequel to Billy the Kid - Shoe
"I am thinking that there was something else going at the same time.Maybe a bad connect where he made up the socket."Which then started arcing when the vacuum was turned on and current started to flow?BruceT
There's probably no need to beat this one to death, but I'm still a little confused. In your previous thread you mentioned an overhead light that stopped working. Now you mention a receptacle that (apparently) was installed some time ago.
Not that it really matters, but I don't see how a receptacle that was installed (at some other time?) caused the light to recently and suddenly stop working.
If, on the other hand, the light stopped working after you replaced the receptacle, you probably should have mentioned that since that should have been a clue that there might be a relationship.
Don: My bad. I really do not know when it stopped working - I can only guess. I was removed from the household for several years. Then - pending the divorce - I got the house. I have not used the MBR for personal reasons for years. I replaced the receptacle perhaps 7 maybe 8 years ago. But I completely forgot I did that until Bill mentioned it could be the culprit. My fault - both ways.Mike
Thanks for the explanation... now I'm happy :-)