touble shooting help

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SDSPARKS

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Was wonder if anyone could provide me with some tips? I have a receptical with 2 romex inside. line and load. The load side goes to a receptical thats the end of circuit. My problem is I'm getting 120 volt to ground on line side.,but not on neutral. however i do get 120 if i go from line hot to load neutral. Receptical does not work.. any ideas

thanks
 
SDSPARKS said:
Was wonder if anyone could provide me with some tips? I have a receptical with 2 romex inside. line and load. The load side goes to a receptical thats the end of circuit. My problem is I'm getting 120 volt to ground on line side.,but not on neutral. however i do get 120 if i go from line hot to load neutral. Receptical does not work.. any ideas

thanks
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I suspect the neutral on the load side is connected to the ground wire. I can't see how elese you could have 120V between the line hot and a disconnected load neutral. Sounds like you also have an open neutral somewhere.

Tip. Kill the circuit and see what is on the circuit. Turn it back on and find the first place where the neutral is showing bad-- It may well be at the panel but I suspect it is in a recep and it is back wired.
 
Sounds like you have an open neutral somewhere.
Try removing the wires from the outlet and test continuity between ground and neutral.
If nothing, the open circuit is ahead of where you are testing the circuit, so try the next box towards the panel.
If you get continuity, then replace the outlet with a new one and test it again.

Edit: Is this a GFCI?
Are you sure it is wired correctly?
 
No this is not a gfi.. recepticals are taken apart and all wires a seperated.. I toned them out to see where they go and they are the only two devices on circuit.. just wanted to see if anyone could think of anything before i open wall and pull new wire in.. i however did not check continuity yet.. was thinking maybe a staple is culprit
 
090201-2031 EST

SDSPARKS:

I do not understand what you said in your post.

I believe what you said is that there is an incoming Romex, you called it line side, that connects to a duplex receptacle. That this receptacle does not work. You measure 120 V from the incoming black wire to the ground wire, but you do not read 120 from black to white. Do you read zero volts, meaning not more than a couple millivolts?

Assuming these are the conditions, then disconnect the incoming Romex from the duplex. Now see what your voltage readings are. If there is a break in the neutral circuit from the main panel to this location, and the hot wire has about 120 V on it relative to ground, then if you use a high impedance meter, my Fluke 27 has 10 megohm input impedance, I expect you will read a substantial voltage from ground to the neutral wire. This results from capacitive coupling from the hot wire to the floating neutral.

I did a quick test with a piece of Romex less than 2 ft long and the ground wire unconnected at either end. This was expedient and accomplishes the desired measurement without disconnecting the neutral in my plug. Thus, I have a floating wire unconnected in the Romex cable. I read 8 V from this floating wire to ground with my Fluke 27.

If your neutral is solidly connected back to the main panel, then the voltage from ground to the neutral should be virtually 0 volts.

If you do not trust the ground wire, then run an extension cord from somewhere that has a known good ground to obtain your ground reference point.

If you read zero voltage, then get an incandescent lamp as a test load. Connect this load to the above said incoming black and white wires. Does the light glow correctly? Make sure the switch is on. Whether the lamp glows or not, then with it connected measure the voltages between a known good ground and hot and separately neutral to ground. At this point report back.

.
 
gar said:
090201-2031 EST

SDSPARKS:

I do not understand what you said in your post.

I believe what you said is that there is an incoming Romex, you called it line side, that connects to a duplex receptacle. That this receptacle does not work. You measure 120 V from the incoming black wire to the ground wire, but you do not read 120 from black to white. Do you read zero volts, meaning not more than a couple millivolts?

Assuming these are the conditions, then disconnect the incoming Romex from the duplex. Now see what your voltage readings are. If there is a break in the neutral circuit from the main panel to this location, and the hot wire has about 120 V on it relative to ground, then if you use a high impedance meter, my Fluke 27 has 10 megohm input impedance, I expect you will read a substantial voltage from ground to the neutral wire. This results from capacitive coupling from the hot wire to the floating neutral.

I did a quick test with a piece of Romex less than 2 ft long and the ground wire unconnected at either end. This was expedient and accomplishes the desired measurement without disconnecting the neutral in my plug. Thus, I have a floating wire unconnected in the Romex cable. I read 8 V from this floating wire to ground with my Fluke 27.

If your neutral is solidly connected back to the main panel, then the voltage from ground to the neutral should be virtually 0 volts.

If you do not trust the ground wire, then run an extension cord from somewhere that has a known good ground to obtain your ground reference point.

If you read zero voltage, then get an incandescent lamp as a test load. Connect this load to the above said incoming black and white wires. Does the light glow correctly? Make sure the switch is on. Whether the lamp glows or not, then with it connected measure the voltages between a known good ground and hot and separately neutral to ground. At this point report back.

.
Click to expand...

The first part of your reply is correct.. The thing i cant figure out is why on the out going peice of romex i am readind 120 volt on the neutral.when i go from incoming romex hot to out going romex neutral...with voltage tester.. I will however try your method thanks..
 
090202-0822 EST

SDSPARKS:

I really did not want to try to figure out, guess, what you were trying to describe after the first outlet.

After you figure out the problem between the main panel and the first outlet, then with all 3 wires that leave this outlet disconnected from the receptcale you can use a meter and a lamp bulb to test each of these outgoing wires to determine if anyone or more are connected to ground or hot. If all 3 of these wires are not floating (not connected to anything else) then you need to find where the cross connection is. The outgoing wires are what you describe as the load side.

A typical digital meter has a high input impedance (10 megohms resistive) and therefore capacitive signals or leakage can produce substantial readings. This is useful. The lamp bulb provides a moderately low impedance. A 100 W is about 144 ohms when hot and in the range of 10 ohms cold (room temperature). Also useful. When using the bulb as a load you may not need the voltmeter across it, brightness may provide sufficient voltage information.

Whenever you do troubleshooting it is desirable to start at a known good point and work outward from that point. It makes no sense to look at a black box that contains many components and from the outside try to guess what is wrong inside that box. You need to get in the box and find something that is working and move from that point.

Consider a vacuum tube radio. If the filaments glow there is no need check for AC input voltage, but you would want to check B+. If that is present, then maybe inject a signal into the grid of the output amplifier. This might simply be your finger or a screwdriver. If you get hum or scratching noise, then you test the stage before this. Next you might inject some signal into the IF (intermeadiate frequency) area. And so on. In a simple radio there might be a few hundred simple combinations of problems. Thus, guessing at the problem is not an efficient approach.

.
 
SD, may I suggest another strategy: plug a 3-prong extension cord into a known-properly-wired and grounded receptacle, and take the female and and a solenoid-type tester (not a voltmeter) with you to the trouble spot.

You'll have a known hot, neutral, and ground to test each wire against. Try all combinations. The only uncertainty will be that you should have either 240v or 0v between the two hots; everything else should be obvious.
 
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