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Kevin
Kevin, Licensed Electrician
Category: Electrical
Satisfied Customers: 2953
Experience:  29 years as a Licensed Electrical Contractor in Illinois, 5 year college Electrical Instructor, Former Electrical Inspector, Diploma in Digital Electronics, Former Illinois Licensed Home Inspector
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A circuit went out; the gfi kept blowing. So I replaced the

Customer Question

A circuit went out; the gfi kept blowing. So I replaced the gfi - twice, and get no power downstream. I get line power but no load power. I took the load off and tested the current on the line wires - ok. I put the tester terminals on the gfi screws where the line wires attach and get no power. What's going on?
Submitted: 1 year ago.
Category: Electrical
Expert:  Kevin replied 1 year ago.

Hello and welcome to Just Answer. My name is ***** ***** I will be happy to assist you with your electrical question.

1) When the LOAD side of the GFCI is disconnected, does the GFCI Test and Reset properly?

2) Do you have an AC voltmeter that has a built-in audible continuity feature?

3) Your comments are conflicting as you mention you get LINE power but then you mention that you put the tester terminals on the GFCI screws where the LINE's attach and get no power? With the LOAD side hot & neutral disconnected, you will either have 120 volts on the LINE side or you won't. Which is it?

4) Are there any other GFCI receptacles installed downstream from the GFCI that you are having problems with or is this the only GFCI on the circuit?

Customer: replied 1 year ago.
The GFI does not reset with load or no load (and I've tried 3 GFIs)
No AC voltmeter
Right - no load wires connected and no power on the GFI screws that screw down on the line wires; the wires themselves test ok
No other GFIs on the circuit
Customer: replied 1 year ago.
if I just connect the load and line wires with no gfi in the circuit, everything works fine
Expert:  Kevin replied 1 year ago.

Thanks for the replies.

1) What part of the home is the GFCI located in? Kitchen, bathroom, garage, outside receptacle, etc? What receptacles are located downstream from the GFCI?

2) Was there any recent electrical performed on this circuit prior to the GFCI not working? Any receptacle replacements, switch replacements, etc?

3) Any chance that you can obtain an AC voltmeter that has a built-in continuity testing feature from a friend or a neighbor?

4) I'm still not understanding what you mean? You keep mentioning that no power on the GFCI screws that screw down on the LINE wires. Yet you also mention the wires test OK. Not sure what type of tester you are using as it needs to be a 2 wire contact tester or an AC voltmeter?

I need to confirm if you have 120 volts on the LINE side GFCI wires from Hot to Neutral and from Hot to Ground and if 0 volts from Neutral to Ground. Do you measure 120 volts on at the GFCI LINE side hot and neutral screws with the LOAD side disconnected?

5) Is the branch circuit configured as a shared neutral circuit? Is the circuit breaker that controls the GFCI a single pole or a double pole breaker? Or 2 single pole breakers with a common trip handle tie?

Customer: replied 1 year ago.
1. Garage - outside outlet and garage door openers
2. No
3. Maybe
4. I know; it makes no sense to me. This tester has two probes on wires. It reads 120 volts Yes, I measure 120 volts from hot to neutral with load disconnected. I haven't tested hot to ground; I will
5. It is a single pole breaker that only controls this line. I'm not sure what you mean about shared neutral circuit
Customer: replied 1 year ago.
Hot to ground reads 120 - that's the problem?
Expert:  Kevin replied 1 year ago.

OK, Thanks for the replies.

1) Temporarily, back the GFCI out from the wall box and disconnect the 2 LOAD side wires. Leave the 2 LINE side wires connected and leave the GFCI hanging out from the wall box. With the breaker in the ON position, hit the GFCI Test and Reset buttons, let me know if the GFCI works correctly under a no LOAD condition. Do not plug anything into the GFCI receptacle when doing this.

2) No, H to G should always measure 120 volts. That is normal.

3) A shared neutral circuit is when having a double pole circuit breaker that feeds 2 separate circuits and the neutral is shared. Is the circuit wired with Romex cable or metal conduit or some other type of cable?

Customer: replied 1 year ago.
1. That's what I did and why I am stumped. With no load the gfi does not reset.
2. I misread - I did H to G instead of N to G; I will try that.
3. Romex
Customer: replied 1 year ago.
N to G is zero volts
Expert:  Kevin replied 1 year ago.

OK, we need to confirm if the circuit is configured as a shared neutral.

1) Remove the cover on the electrical panel. Locate the branch circuit breaker and trace the hot wire from the breaker up to the Romex cable. Inside the Romex cable, how many wires? 1 black, 1 white and 1 bare copper ground or does the Romex cable contain a red wire? If it contains a red wire, trace the red wire inside the panel........does it land on a circuit breaker immediately above or below the GFCI circuit breaker?

2) OK, good... N to G should always be at 0 volts.

Customer: replied 1 year ago.
There are bunches of white and black wires and one red one . The red one goes down to the lowest breaker - like 5 or 6 breakers below the garage one
Expert:  Kevin replied 1 year ago.

Thanks:)

1) So you are saying that the Romex cable contains 1 black, 1 white, 1 red and 1 bare copper ground correct?

2) Does the GFCI breaker have the black wire and then there is a red wire landing on another single pole breaker below? The black and red wire are from the same Romex cable sheath, correct?

3) Locate the white neutral wire as it leaves the Romex cable. Does only the 1 white neutral from the cable sheath land on the neutral bus bar or does the white wire from the cable sheath split out into two separate white neutrals and contains a wire nut inside the panel?

Customer: replied 1 year ago.
There are several separate romex wires containing black and white wires and a separate red one (as far as I can tell). Not one wire with red white and black.
The red wire goes to a double pole breaker on the bottom of the box - several breakers below the garage breaker
White neutral is single.
Customer: replied 1 year ago.
If everything works with the gfi out of the circuit, I have to think it's the gfi except that I have tried three of them. But you know way more than I do
Expert:  Kevin replied 1 year ago.

OK, thanks.

1) Based on your reply, doesn't sound like the circuit was wired as a shared neutral circuit then.

2) Are you positive that you have correctly identified the GFCI LINE and LOAD wires? If the LINE and/or LOAD wires are not wired correctly or are mixed up, the GFCI won't reset.

2) Since the GFCI still trips under a no LOAD disconnected condition, the next logical step would be to confirm that no continuity exists on the circuit.

Flip the breaker to the OFF position and remove the GFCI circuit hot wire from the breaker. Remove the branch circuit white neutral from the neutral bus bar and remove the branch circuit bare copper from the neutral or separate ground bar. Now the circuit is completely disconnected with no power to it.

At the GFCI receptacle, disconnect the LINE and LOAD wires from the GFCI. Remove the GFCI. Spread all 3 wires apart inside the panel and spread apart the 3 LINE side wires at the GFCI. With a continuity tester, check for any continuity on the 3 open wires. Go from H to N, H to G and N to G. The purpose of this is to check if any of the 3 wires are shorting out from the panel to the GFCI. Let me know the results............Thanks............Kevin:)

Customer: replied 1 year ago.
Kevin, I appreciate your help but I'm at the limit of my knowledge and I don't have a continuity tester. Your answer makes sense but I don't like messing around in the circuit box so I'm going to call an electrician. But thanks for your advice - you helped a lot and educated me in the process.
Expert:  Kevin replied 1 year ago.

OK, no problem, I understand.

If you have any additional questions or change your mind, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks..............Kevin:)

Expert:  Kevin replied 1 year ago.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks...............Kevin:)

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