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Electrical issues with living room light - continuously blowng bulbs.

Electrical issues with living room light - continuously blowng bulbs.

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Old 12-13-10, 06:58 AM
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Electrical issues with living room light - continuously blowng bulbs.

We were replacing a ceiling fan in my dad's house that we believed to not work correctly. Now I'm afraid the problem is more serious. We replaced the fan with a normal light fixture and, within a matter of minutes, four of the five bulbs blew. We thought it may have been related to an Encon fan controller, so we removed it. Retested the light, and bulbs blew again (this time within 10 minutes, so they lasted a little longer).

The scary part came a few minutes later. While the power was off (at the circuit breaker), my fiancee tried to vacuum in my dad's bedroom (plugged into an adjoining wall, but on a different circuit, adjacent in the breaker box). When she turned on the vacuum, the light in the living room came on, though dimly, and she received a light shock from the vacuum cleaner. She immediately turned off the vacuum. We checked it later in another plug, and it worked without problem.

Where should we start? I will be back there next weekend, this time armed with my volt meter.

Thanks, in advance, for any help!
 
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Old 12-13-10, 07:07 AM
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Sounds like you have an improper connection at the new fixture box. Can you tell what connections you made when you installed the fixture?

I suspect you might have crossed some wiring and are supplying too much voltage or are using the neutral improperly.
 
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Old 12-13-10, 07:17 AM
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I agree. I have a feeling you inadvertently opened a neutral on a multi-wire circuit. This would cause 240 volts across the circuit. You may have damaged the vacuum or other things plugged into that circuit.
 
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Old 12-13-10, 10:46 AM
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Only two wires at the new fixture box. No other changes other than connecting these to the new light fixture.

My dad had problems keeping light bulbs in the fan for as long as he owned the house. We thought the problem was in the fan. Now I suspect the wiring.
 
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Old 12-13-10, 10:51 AM
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Originally Posted by Tolyn Ironhand View Post
I agree. I have a feeling you inadvertently opened a neutral on a multi-wire circuit. This would cause 240 volts across the circuit. You may have damaged the vacuum or other things plugged into that circuit.
Thanks for your comment.

Everything still working, and it seems to be intermittent. Don't know why it happened when she plugged in the vacuum, unless the problem is in that outlet.
 
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Old 12-13-10, 10:55 AM
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Originally Posted by pcboss View Post
Sounds like you have an improper connection at the new fixture box. Can you tell what connections you made when you installed the fixture?

I suspect you might have crossed some wiring and are supplying too much voltage or are using the neutral improperly.
Only two wires at the new fixture box. No other changes other than connecting these to the new light fixture.

My dad had problems keeping light bulbs in the fan for as long as he owned the house. We thought the problem was in the fan. Now I suspect the wiring.
 
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Old 12-13-10, 11:11 AM
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Tell us how many cables at the switch box and how they are wired. Also how many cables at the receptacle where the vacuum was plugged in? Is the breaker on this circuit single pole or double pole? If single pole are the breakers for each of the two circuits next to each other?
 
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Old 12-13-10, 12:11 PM
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Originally Posted by ray2047 View Post
Tell us how many cables at the switch box and how they are wired. Also how many cables at the receptacle where the vacuum was plugged in? Is the breaker on this circuit single pole or double pole? If single pole are the breakers for each of the two circuits next to each other?
I'll have to double check, but it seems like there were two sets of wires coming into the switch. I assume that one set is going to the second switch for the light (sorry, I forgot to mention that earlier).

I have not checked the plug outlet.

The breaker on this circuit is single pole. I believe the circuits are next to each other on the board.
 
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Old 12-13-10, 01:36 PM
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I assume that one set is going to the second switch for the light
So this is a three-way light controlled at two locations That means you should have 3-conductor cable at each switch since you have written you have only a single 2-conductor cable at the light. Is that correct?
 
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Old 12-13-10, 02:50 PM
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Originally Posted by ray2047 View Post
So this is a three-way light controlled at two locations That means you should have 3-conductor cable at each switch since you have written you have only a single 2-conductor cable at the light. Is that correct?
You are correct in that it is only a 2-conductor cable at the light. I am not sure about it being a 3-conductor cable at each switch. I'm used to 3-wire having a white, black, and red wire. To the best of my memory, I only have white and black wires at the switch.

Thanks again for all your help. I apologize, but I'm going from memory here.
 
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Old 12-13-10, 03:57 PM
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I am not sure about it being a 3-conductor cable at each switch. I'm used to 3-wire having a white, black, and red wire. To the best of my memory, I only have white and black wires at the switch.
At this point if it is a three-way and no 3-conductor cable maybe it is a some kind of Carter three-way or they used the ground as a conductor. Neither way is code compliant.

Lets start back at the basics just so I'm sure we are on the same page. The light is controlled by two different switches in two different places?

Are the switches marked on/off? Do they have a green ground screw? Do they have two brass screws and a dark screw? Is there a bare ground and which screw is it connected to. Ok I'll have more questions but I'll wait for those answers.
 

Last edited by ray2047; 12-13-10 at 04:16 PM.
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Old 12-13-10, 05:07 PM
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has anyone checked the voltage? that is probablt the problem.
 
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Old 12-13-10, 06:26 PM
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Originally Posted by Tolyn Ironhand View Post
I agree. I have a feeling you inadvertently opened a neutral on a multi-wire circuit. This would cause 240 volts across the circuit. You may have damaged the vacuum or other things plugged into that circuit.
I suspect TI is closest to the problem. There is probably a poor or bad neutral connection on a multi-wire branch circuit intermittently allowing 240 volts across the circuit.
 
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Old 12-14-10, 08:04 AM
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Originally Posted by CasualJoe View Post
I suspect TI is closest to the problem. There is probably a poor or bad neutral connection on a multi-wire branch circuit intermittently allowing 240 volts across the circuit.
Thanks for all of your help on this. The problem is finding out where that poor connection is. Some info that may need to be stated:

1. The house was built in 1970. There is a reasonable chance that some of the wiring may not have passed code today.

2. The problems existed BEFORE I installed the new light fixture. We just thought it was a short in the ceiling fan causing the problems.

3. Somehow, the circuit between the living room and the bedroom are connecting, at least at one outlet. I believe that is the source of the stray voltage. The problem is that I can't figure out how. All I know is that when the vacuum cleaner was plugged in, the lights in the living room came on.

I'll be checking the plug, all switches, and any junction boxes in the attic this weekend when I'm there again. Thanks for all of your help.
 
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Old 12-14-10, 10:27 AM
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I would still like info on that 3-way switch pair. If it is only 2-conductor cable a ground wire used as a conductor might explain your problem also.
 
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Old 12-14-10, 06:05 PM
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stating that your house was from the 70's, when everything was backstab, a neutral probably worked loose.
 
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Old 12-14-10, 06:17 PM
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Originally Posted by dochort View Post
1. The house was built in 1970. There is a reasonable chance that some of the wiring may not have passed code today.
It would not have to pass today's code. It is grandfathered in for when it was installed.

Originally Posted by dochort View Post
3. Somehow, the circuit between the living room and the bedroom are connecting, at least at one outlet. I believe that is the source of the stray voltage. The problem is that I can't figure out how. All I know is that when the vacuum cleaner was plugged in, the lights in the living room came on.
These are classic symptoms of an open neutral in a multiwire circuit. You also mentioned that the two breakers are right next to each other. Also a sign of a multiwire circuit. If you want to confirm this, and you feel comfortable doing so, remove the panel cover. From the two breakers you should find 2 colored wires (not white or green) grouped with only one white. This would be a multiwire circuit.

Maybe these pictures might help (Please excuse the poor drawing ):



This picture is a normal multiwire circuit. Current flows from the breakers, through the light or vacuum, and then back on the neutral. The neutral does not get overloaded because it only carries the imbalance of breaker A and B. (Note: Yes, I know current flows both ways, I'm just using the KISS method )



This picture shows the same circuit with a broken neutral. As you can see there is still a path for current to travel but it requires two things (the light and the vacuum) to be connected on the circuits. These two items are now in series on the circuit, and there is 240 volts across the circuit. This is why the light came on when the vacuum was turned on as it completed the circuit. The resistance of each item will determine which of the two 120 volt devices will take the hit but I think we figured out it is the old/new fan.

I think you need to start taking things apart and find the bad connection.
 
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Old 12-15-10, 08:15 AM
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Originally Posted by ray2047 View Post
I would still like info on that 3-way switch pair. If it is only 2-conductor cable a ground wire used as a conductor might explain your problem also.
I'll look at that this weekend. Thanks for the help!
 
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Old 12-15-10, 08:18 AM
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Originally Posted by Tolyn Ironhand View Post

I think you need to start taking things apart and find the bad connection.
Thanks for the great info. I'll let you know how it goes this weekend. Thanks again for all the help.
 
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