Electrical Issue

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Old 03-26-17, 07:55 PM
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Electrical Issue

I'm having a weird issue. The other day my porch light and several other lights in my house went out. I checked the breaker but it hasn't been tripped. I then looked for gcfi plugs that might have tripped but couldn't find one. I noticed a plug in my garage next to my opener. It is a two prong plug with a switch. The switch was in the off position, as soon as I turned it to on the power returned to all those lights.

Now here's the weird thing. I tried replacing the plug with a regular grounded plug and light switch combo, however I cannot get those same lights back on. The plug itself is on a different breaker than the lights that are out. When both breakers are one part of what each breaker controls is on and part is off.

Any help or ideas about this would be appreciated.

Thanks.
 
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Old 03-26-17, 08:49 PM
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noticed a plug in my garage next to my opener. It is a two prong plug with a switch.
Do you mean a receptacle and switch combo with no ground hole?

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And you replaced it with a receptacle /switch combo.

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The plug itself is on a different breaker than the lights that are out.
How many wires in the switch box? What colors and how did you connect them? Did you break the tab between switch and receptacle?

Terminology: A plug is male and goes into a female receptacle.
 
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Old 03-27-17, 04:36 AM
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Yes it was an ungrounded receptacle, that I'm trying to make grounded.

There are three wires coming in, white, black, and bare. There are no wires going out. I have a voltmeter and checked the wires, the white wire is hot giving 120v when I check it with the ground. The black wire should be my common, but when I check it with the ground I get around 40v.

I did not break the tab.
 
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Old 03-27-17, 05:57 AM
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I have a voltmeter and checked the wires, the white wire is hot giving 120v when I check it with the ground.
That is wrong.
The black wire should be my common
No such thing in this application. It should be a hot.
when I check it with the ground I get around 40v.
Probably actually close to 0v if you are using a digital meter.

With all wires disconnected tell us voltage black to white.
The plug itself is on a different breaker than the lights that are out... I noticed a plug in my garage next to my opener. It is a two prong plug with a switch. The switch was in the off position, as soon as I turned it to on the power returned to all those lights.
But now you wrote:
There are three wires coming in, white, black, and bare. There are no wires going out.
So that couldn't have controlled the other lights unless it is a switch loop in which case the receptacle wouldn't have worked..
The plug [receptacle] itself is on a different breaker than the lights that are out. When both breakers are one part of what each breaker controls is on and part is off.
Is one breaker on top of the other? Does one breaker have a red wire.

Let's start with the voltage reading I suggested and go from there.
 
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Old 03-27-17, 02:06 PM
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There is only 30-40v when I check the white and black wires. I checked other wires on the same breaker and get the same result.
 
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Old 03-27-17, 03:21 PM
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At the breaker check power from the breaker to neutral.
 
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Old 03-27-17, 04:17 PM
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If you mean the bolt on the breaker holding the black wire and the strip of metal with the other bolts, it's 120v.
 
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Old 03-27-17, 05:16 PM
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bolt on the breaker holding the black wire and the strip of metal with the other bolts, it's 120v
So you need to open all receptacle, switch. and ceiling boxes and check all connections, redo all wire nuts and move any backstabs on non GFCI receptacles to the screws.
 
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Old 03-27-17, 06:31 PM
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So when I check the black and bare wire I get 120v.
 
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Old 03-27-17, 06:35 PM
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So when I check the black and bare wire I get 120v
You should also get ~120v black to white and ~0 white to bare. It is best to use an analog multimeter to avoid spurious readings. If you use a digital anything under 100 volts may really be just induced voltage.
 
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Old 03-27-17, 06:39 PM
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So I get 30-40 for the white to black and 30-40 for bare to white.
 
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Old 03-27-17, 06:51 PM
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So I get 30-40 for the white to black and 30-40 for bare to white.
If that is with a digital multimeter consider the circuit dead. What about black to bare.

Just info: In a properly working circuit your readings should be:
  • Black to white = ~120v ( 10%)
  • Black to ground = ~120v
  • White to ground = ~0v

Also you need to check your meter by testing the voltage between the wide and narrow slots on a known good recptacle.
 
 

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