Low Voltage on circuit.

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cloakingknight

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I recently plugged in a dewalt drill charger and it must have shorted something. I couldnt turn on the light that is on the same circuit. Easy, just flip the breaker. Went to the panel and found that the breaker did pop. I flipped it off and on, went back expecting every to be work. Nope didnt work. I thought maybe bad outlet, switched it out, same problem. Used a non contact pen to test, and every outlet, switch beeps, but no power to power any devices.

I thought it was a gfi issue, which I do have 2 gfi on the circuit, I pressed restart on both and nothing happened. I disconnected one of the gfi, didnt bother with the other one after I hooked up my voltmeter.


Volt meter results.

Hot and neutral. Now 1.9 - 2.4.
Hot and ground .5v
Neutral and ground is .4v


Voltage at the beaker and it is reading 122v. I replaced it anyways. Now one of the outlet read 1.2v. So its not the breaker.
After installing the new circuit breaker, some outlet have no voltage between hot and neutral.

Note: all the receptacle was working before plugging in the battery charger.

Not sure why I get so low voltage.
 

Reach4

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Broken or loose wire?

Defective or mis-wired GFI? Does a GFCI outlet send power on to other outlets?

Note that digital voltmeters are high impedance devices.
 

Cacher_Chick

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The low voltage you are measuring can be ignored. You have an open circuit and are going to need to trace the path of the wire to determine where the problem is. It could be that there is another GFCI upstream which is feeding the circuit, a bad connection, damaged wire, etc.
 

cloakingknight

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All connections were working till I plugged the battery charger. I'm going to remove both gfi from the circuit and see if it works.

Else, might be a damaged wire.
 

WorthFlorida

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GFCI’s can go bad. I’ve had a few myself. When you cannot reset a GFCI means there is no power. Don’t discount that the charger. It could be bad.
 
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cloakingknight

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Disconnected Both GFIs and still just 1.2V. on all the lines. I think i pin pointed the first receptacle and it shows the low voltage. And the breaker shows 122V. Not sure the possibility of that burning out? I believe it is a direct run to the first receptacle.
 

WorthFlorida

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What do you read from the neutral to ground? Then from the blk (power) to the neutral and then from ground?
 

Jadnashua

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You need to check any wire nuts and screws along the way to verify you have good connections. While you're at it, look for any scorch marks that may be the location of where the overcurrent event took place.

Does the charger work on another circuit, or does it blow that CB as well?

If you pull the breaker, take a close look at the bus bar where it connects to the panel and the back of the breaker for corrosion or burn marks. When pulling it out or pushing it back in, how much tension is there when making contact with the bus bar? It needs fairly good tension to get a low-resistance connection. Long-term, high-current use can weaken the spring tension.

They do make circuit testers that inject a signal into the line that can help you locate where there's a break. The better ones can get expensive, but sometimes the cheap ones are good enough. The better ones can sometimes tell you the distance to the problem as well.

Stacking GFCI devices isn't always a good idea. Using one with a feed-through protects everything downstream, and, sometimes, it's easier to use a GFCI CB if everything on that circuit needs protection. Retrofitting a receptacle, if you only want one in a circuit, can take some experimentation t0 locate the first item in the path.
 

cloakingknight

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I will disconnect the first receptacle, or the one I think it is and see if anything else works.

At the panel, I saw a red wire connected to the breaker. After some research, it is from the transfer switch. The black wire from transfer switch is connected to the original black wire using a wire nut. I was hoping it reads low, so it would be an easy work around. But it read 122v, so its further downstream. So the wire from the panel to the first receptacle (dome light) might be damaged??
 
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cloakingknight

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You need to check any wire nuts and screws along the way to verify you have good connections. While you're at it, look for any scorch marks that may be the location of where the overcurrent event took place.

Does the charger work on another circuit, or does it blow that CB as well?

If you pull the breaker, take a close look at the bus bar where it connects to the panel and the back of the breaker for corrosion or burn marks. When pulling it out or pushing it back in, how much tension is there when making contact with the bus bar? It needs fairly good tension to get a low-resistance connection. Long-term, high-current use can weaken the spring tension.

They do make circuit testers that inject a signal into the line that can help you locate where there's a break. The better ones can get expensive, but sometimes the cheap ones are good enough. The better ones can sometimes tell you the distance to the problem as well.

Stacking GFCI devices isn't always a good idea. Using one with a feed-through protects everything downstream, and, sometimes, it's easier to use a GFCI CB if everything on that circuit needs protection. Retrofitting a receptacle, if you only want one in a circuit, can take some experimentation t0 locate the first item in the path.


I replaced the breaker same thing. I remove one of the outlet and no power to both gfis. Before that, I disconnected both gfis still no luck.
 

WorthFlorida

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Don’t get so hung up on these very low voltage readings using a digital meter. Some guys call it back feed. A very common practice at one time was to run 14-3 or 12-3 to a location from two breakers and the runs would split going to different locations. BLK, RED & WHT. The WHT neutral is a shared current carrying wire. Turn off the breaker for the RED wire and there is still current on it from the still connected BLK wire.

Right now I’m confused as what the problem is at this point. Sorry but it could be me.
 

hj

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Your neutral to ground and hot to neutral imply that you have an "open" neutral and something, i.e., a GFCI, light with the switch turned on, or a turned on , is cross feeding the power into the neutral.
 

cloakingknight

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Below is the dome light. The readings are:
Ground to neutral 115v.
Hot (Long black wire with clip to red) to neutral 1.3v
Hot to ground 123.5v


Bypass 2 hot wire (short back wire) to neutral 1.3v
Bypass 2 hot wire to ground 124.2v
 

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cloakingknight

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I separated the in and out wires.

The in wire readings:
Hot to ground 125.5v
Neutral to ground is 0v
Hot to neutral is 0v

seems like neutral to ground should be 0v, but is hot to neutral be 0v?
 

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TVL

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I separated the in and out wires.

The in wire readings:
Hot to ground 125.5v
Neutral to ground is 0v
Hot to neutral is 0v

seems like neutral to ground should be 0v, but is hot to neutral be 0v?


It appears HJ nailed it in post 13: Loose neutral (somewhere between where you took the voltage readings and the electrical panel the neutral wire has come loose)
 

Jadnashua

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Plus minus 5% is common when dealing with supply voltages. Then, you have to take into account the accuracy of the meter you're using. Most you would probably be using aren't all that accurate, and probably have not been calibrated since leaving the factory, if they ever were.

Don't sweat the really low voltages. It's easy to induce some low voltage, but if you were using an analog meter, you'd probably measure zero. A typical DMM might have 100Mohm or higher input impedance, a typical analog one maybe 20Kohms. You can easily get different readings between the two types of meters depending on exactly what's in the circuit.

Typically, you'll get almost identical readings between L-N and L-G. Ideally, there's be no voltage between N-G.
 

cloakingknight

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Went to attic and took some pic.
The wire coming in should be the first receptacle. Following the hot wire/open neutral, it runs directly to the back of the house. And there are about 8 wires coming from that area. Should be going to the panel. House is a hi ranch and the wiring mainly goes to the attic, then feeds to bottom floor. Anyone know how I can test for continuity on just the neutral. I am able to pin point the neutral in the panel, and even moved it to another slot. Still no luck.
 

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lampmoon

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The low voltage you are estimating can be overlooked. You have an open circuit and will need to follow the way of the wire to figure out where the issue is. It may be the case that there is another GFCI upstream which is bolstering the circuit, an awful association, harmed wire, and so on.
 

Cacher_Chick

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Went to attic and took some pic.
The wire coming in should be the first receptacle. Following the hot wire/open neutral, it runs directly to the back of the house. And there are about 8 wires coming from that area. Should be going to the panel. House is a hi ranch and the wiring mainly goes to the attic, then feeds to bottom floor. Anyone know how I can test for continuity on just the neutral. I am able to pin point the neutral in the panel, and even moved it to another slot. Still no luck.

If you have a multimeter, you can use a length of wire to test for continuity back to the panel. The conductors need to be disconnected in the panel when you are testing end to-end.
The neutral and ground should be bonded together if it is the main panel, so there should be continuity between neutral and ground anywhere in the house.
 
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