How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Mike Your Own Question
Mike
Mike, Master Electrician
Category: Electrical
Satisfied Customers: 1425
Experience:  Licensed Master Electrician - OnQ Certified Data Voice Audio Video Installer
11762411
Type Your Electrical Question Here...
Mike is online now
A new question is answered every 9 seconds

When I isolate my kitchen outlets from the electrical system

Customer Question

When I isolate my kitchen outlets from the electrical system there is a 60v differential between the gfi power lead and the power lead of the isolated circuit. The gfi trips if it is hooked up. What is wrong?
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) Does the LINE side of the GFCI have a constant 120 volts on it?

2) At the GFCI LINE side, measure from Hot to Neutral, Hot to Ground and from Neutral to Ground. What are the 3 voltage measurements?

Customer: replied 1 year ago.
the line side has a constant 120 v. Hot to neutral 120v , hot to ground 120v , neutral to ground 0v
Expert:  Kevin replied 1 year ago.

Thanks for the replies.

1) Those are all good voltage measurements.

2) Temporarily disconnect the LOAD side hot and neutral at the GFCI, does the GFCI still trip when powered?

3) Are the kitchen receptacles configured as a shared neutral circuit? Is the circuit breaker that controls the GFCI a double pole circuit breaker or 2 single pole breakers that have a common trip handle?

Customer: replied 1 year ago.
Hot to neutral on all the subsequent outlets has 0 continuity infinite ohms
Expert:  Kevin replied 1 year ago.

1) That is normal. H to N should never have continuity. Infinite ohms means the H to N conductors are an open loop and are not shorted together.

2) Temporarily disconnect the LOAD side hot and neutral at the GFCI, does the GFCI still trip when powered?

3) Are the kitchen receptacles configured as a shared neutral circuit? Is the circuit breaker that controls the GFCI a double pole circuit breaker or 2 single pole breakers that have a common trip handle?

Customer: replied 1 year ago.
The gfi is working well with the dining room outlets which is a separate circuit . The four kitchen outlets have continuity between the neutrals continuity between the power sides and continuity between the grounds. The breaker is a single 20 A and has no common trip handle. The gfi only trips if connected to the kitchen outlets even when the dining room outlet circuit is totally disconnected
Customer: replied 1 year ago.
The kitchen outlets connect to no other circuits
Customer: replied 1 year ago.
Are you still there?
Expert:  Kevin replied 1 year ago.

Thanks for the replies.

1) If continuity exists between H to N, then there is a short somewhere on the circuit that is causing the GFCI to trip.

2) Is the dining room part of the same kitchen circuit or 2 different circuits?

Customer: replied 1 year ago.
There is no continuity between the hot and neutral. The dining room circuit I disconnected to test the kitchen circuit alone. Only the kitchen circuit trips the gfi. the kitchen circuit has never worked in this house since installation. I reconnected the dining room circuit to the gfi and it works perfectly. It was then I noticed there is a 60v differential between the hot line side of the gfi and the hot side of the disconnected kitchen circuit.
Customer: replied 1 year ago.
The dining room is a separate circuit .
Expert:  Kevin replied 1 year ago.

Are both breakers (kitchen and dining room) stacked on top of each other on either the left or right hand side of the electrical panel?

Customer: replied 1 year ago.
There is no dining room circuit breaker it operates off the kitchen gfi breaker. There is a separate gfi kitchen breaker for the other two kitchen outlets and they are stacked and therefore I assume on different phases
Customer: replied 1 year ago.
The top one operates the problem circuit and the one just under it. Operates the second kitchen gfi. Could the second circuit be inducing a 60 v differential in the first?
Expert:  Kevin replied 1 year ago.

You previously mentioned that the dining room circuit is a separate circuit.

Remove the door from the panel, trace the hot wires terminating to each of the kitchen breakers. If both of these hot wires resided within the same Romex cable. If Romex cable was installed, locate and confirm if only (1) white neutral lands on the neutral bus bar. Not sure if you have Romex cable installed or what the wiring scheme that was installed?

I suspect you have a shared neutral circuit. If you do, whoever installed the stacked circuit breakers was not a competent electrician. Shared neutral circuit must have a common trip handle tie or use a double pole breaker.

If one kitchen breaker is a GFCI type and the other breaker is a regular breaker, then a shared neutral is the cause of the problem.

Expert:  Kevin replied 1 year ago.

1) Are both kitchen breakers a GFCI type or only 1 is a GFCI type?

2) Does the kitchen countertop or dining room contain any GFCI receptacles or just the normal duplex receptacles (non-GFCI type)

Customer: replied 1 year ago.
I could shut off the second and see if the 60 v disappears. the dining room circuit ends in the box with the kitchen gfi in question not at the panel. The electrician mentioned to the owner that there weren't enough breakers by the owners recollection. I'll check the panel for a common neutral.
The Romex is cut back so far at the box that identification of the neutrals for both circuits is not possible. I reconnected the kitchen circuit in question to the gfi and shut off the second kitchen circuit breaker at the box but it still throws the gfi off. I'm at a loss as to how to proceed.
Customer: replied 1 year ago.
I connected only the neutral side of the circuit in question (disconnected the power side at the load) and it still throws the gfi off
Expert:  Kevin replied 1 year ago.

1) Do the hot wires at each breaker and the one neutral wire extend to one common 3 wire Romex cable? Does 1 breaker contain a black wire and the 2nd breaker contains a red wire?

2) Are both kitchen breakers a GFCI type or only 1 is a GFCI type?

3) Does the kitchen countertop or dining room contain any GFCI receptacles or just the normal duplex receptacles (non-GFCI type)

Expert:  Kevin replied 1 year ago.

1) Do you have access to where the Romex cable is connected into the panel? Or is the panel surrounded by drywall or other wall finishing?

2) I need to confirm if the 2 circuits were wired using a 3 wire (1 black, 1 red and 1 white) Romex cable?

Customer: replied 1 year ago.
The panel is surrounded by plaster the gfi label at the box is written in by hand the breakers are one pole no common trip and are not labeled commercially as gfci the gfi receptacles are of course with a red reset button. Is there any other way to determine if the neutral is common? All the Romex have a black a white and a copper lead at the receptacle.
Customer: replied 1 year ago.
None of the Romex have a red lead
Expert:  Kevin replied 1 year ago.

OK, thanks.

1) Are both kitchen breakers a GFCI type or only 1 is a GFCI type?

2) Does the kitchen countertop or dining room contain any GFCI receptacles or just the normal duplex receptacles (non-GFCI type)?

3) If the breakers both contain black wires, you should be able to visually trace the 2 white neutral wires inside the panel. Are the 2 white neutrals spliced and pigtailed together to only 1 neutral landing on the neutral bus bar or are the 2 white neutrals individually terminated to the neutral bus bar?

Customer: replied 1 year ago.
Only a black,a white and a copper ground
Expert:  Kevin replied 1 year ago.

Yes, I know that.

Please answer these questions?

1) Are both kitchen breakers a GFCI type or only 1 is a GFCI type?

2) Does the kitchen countertop or dining room contain any GFCI receptacles or just the normal duplex receptacles (non-GFCI type)?

3) If the breakers both contain black wires, you should be able to visually trace the 2 white neutral wires inside the panel. Are the 2 white neutrals spliced and pigtailed together to only 1 neutral landing on the neutral bus bar or are the 2 white neutrals individually terminated to the neutral bus bar?

Customer: replied 1 year ago.
The black leads at the box can be traced only to where they enter the box and cannot be matched to their neutral counterpart to see if they have been wired together or connect separately to the neutral bar.
Expert:  Kevin replied 1 year ago.

Please answer these questions?

1) Are both kitchen breakers a GFCI type or only 1 is a GFCI type?

2) Does the kitchen countertop or dining room contain any GFCI receptacles or just the normal duplex receptacles (non-GFCI type)?

Customer: replied 1 year ago.
The gfci receptacles in the kitchen are the only indication both kitchen circuits are gfci other than the black marker gfi. Written in at the box . There are no red wires. The breakers are labeled culler hammer type br120 120/240 HACR type cir bar 1 pole j-969. They are identicle.
Customer: replied 1 year ago.
Each kitchen circuit has a separate gfi receptacle there are two one for each circuit
Expert:  Kevin replied 1 year ago.

So each of the kitchen breakers do not contain a TEST button, is that correct?

Customer: replied 1 year ago.
All remaining receptacles are normal duplex non gfi type
Expert:  Kevin replied 1 year ago.

1) How many Romex cables enter into the panel knockout opening for the circuits? Multiple cables enter within the same knockout?

2) So each of the kitchen breakers do not contain a TEST button, is that correct?

Customer: replied 1 year ago.
Both of the receptacles contain a test and reset button. There is no test button on the breakers in the bo
Customer: replied 1 year ago.
There are a plethora of cablesintering the box . I tried to follow the two black hot leads from their circuit breakers but it is not possible to find their matching neutral leads. It is packed so tightly and devoid of their original housing
Customer: replied 1 year ago.
Each of the two kitchen circuits contain only one gfi receptacle each and it is located at the initiation of the circuit
Customer: replied 1 year ago.
The kitchen breakers at the box contain no reset button only the two receptacles in the kitchen contain reset red and black test buttons
Customer: replied 1 year ago.
Multiple cables enter the box but no cable coverings just the wires with their respective colored insulation. The coverings were stripped off further inside.
Expert:  Kevin replied 1 year ago.

Did either of the GFCI's originally have a LOAD side connection?

When you re-wired the GFCI's, did you wire them with a LOAD side connection?

You previously mentioned that a portion of these circuits have never worked? Please comment on what did not work correctly?

Customer: replied 1 year ago.
I have only worked with the receptacle box which is at the head of four kitchen outlets it being the fifth. None of these outlets including the gfi receptacle worked ever . I replaced the gfi receptacle it still did not work. There are three cables that enter the box. One is the power cable, one the dining room outlet circuit cable and one is the kitchen circuit cable from the four duplex outlets. The other kitchen gfi is a separate circuit with a separate breaker at the box and a separate gfi receptacle In the kitchen. When I connect the power leads to the line and ground the gfi receptacle woks fine. When I connect the dining room to the load side it still works fine. When I disconnect the dining room cable and connect only the neutral of the kitchen circuit and not the power side the gfi trips and will not work at the gfi receptacle . The circuit breakers have never tripped. When I connect the power lead as well to the load terminal the gfi trips in the kitchen just like it does when only the neutral lead is connected to the load side. Additionally when the load neutral is connected there is a 60 v potential in between the line power lead and the black power lead of the kitchen circuit I don't understand.
Expert:  Kevin replied 1 year ago.

Thanks for the replies.

I still suspect the 2 circuits are configured as a shared neutral.

Locate the 2 hot wires from each breaker. Trace them and they should both enter into the same panel knockout opening. Once this is confirmed, trace the white neutrals that enter into the same panel conduit knockout opening.Turn the main panel breaker to the OFF position and then temporarily remove one white neutral wire at a time that originates from the same cable bundle. Then turn the main breaker back to ON. Then identify which circuit in the home does not work.

No matter how many wires reside in the panel, you can still trace both of the black hots and see if they wind up in the same conduit knockout opening. If they do, the corresponding white neutrals also reside in the same conduit opening where the cable connector is locked down with a lock nut washer. This can now isolate the quantity of white neutrals. Follow each neutral to the neutral bus bar and disconnect one at a time as outlined above.

Since the exterior Romex cable sheath is not visible from inside the box, this is the quickest method to confirm if a shared neutral was wired. After testing the receptacles in the kitchen and dining room and they are all dead but yet both breakers are ON,this will confirm if a shared neutral was configured.

Customer: replied 1 year ago.
Dear *****, the box has only one vey large knock out through which all but a couple of wires protrude. It will be a while before I can get this accomplished thank you for your help today
Gari Spire
Expert:  Kevin replied 1 year ago.

No problem, glad to assist.

1) Unfortunately, sounds like the electrical panel was not wired by a competent electrician or a competent DIY'er. Per code, all Romex cables should have had the exterior white or yellow Romex insulation of the cable penetrating into the panel so that you can visually trace the corresponding conductors within the same NM Romex cable sheath.

2) Another method that can be used to confirm if a shared neutral conductor was installed is to eventually disconnect those neutrals one at a time and then use a continuity tester on the 2 kitchen circuits. If continuity is achieved on both circuit neutrals from any of the downstream receptacles, then this is wired as a Multi-Wired Branch Circuit (shared neutral circuit).

3) The tripping of the GFCI receptacles suggest a shared neutral circuit was installed. If confirmed that the circuit was wired as an MWBC then having 2 regular circuit breakers wired to 2 separate down stream GFCI receptacles along with LOAD side connections for non-GFCI receptacles will always trip an upstream GFCI receptacle. There are specific wiring methods used on an MWBC circuit with GFCI protection.

4) The GFCI is tripping because of one of the following:

A) An MWBC circuit was configured and LOAD side connection were terminated to each of the GFCI's

or

B) A direct short circuit exists causing the GFCI to trip

or

C) The incorrect neutral from another circuit was terminated.

5) If the 2 kitchen circuits were configured as a MWBC (shared neutral), this is a common issue as many electricians or DIY'ers do not install these circuits correctly (they use single pole breakers instead of double pole breaker types or the 2 single pole breaker don't contain a common trip handle tie. Most electricians do not label the conductors accordingly.

6) If confirmed the 2 circuits were wired as MWBC, these are the reasons I never recommend to wire any circuit as MWBC. They are nothing but a hassle to troubleshoot since they are seldom ever labeled. Unfortunately, the National Electrical Code only requires that an MWBC circuit resides within the same cable sheath or same conduit or the conductors be tie-wrapped together.

You are unable to even visually determine the cable sheath colors that enter into the panel. Multiple cables all bundled into the same NM Romex box connector. These are also indications of code violations and poor workmanship on whoever installed the branch circuit cables to the electrical panel.

7) In summary, I don't know if you have a MWBC (shared neutral circuit) or if a short is causing the tripping or if the wrong neutral was connected. Somehow, the single neutral or the 2 neutrals that feed these circuits need to be confirmed. For starters, an MWBC circuit needs to either be confirmed or ruled out.