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Kevin, Licensed Electrical Contractor
Category: Electrical
Satisfied Customers: 3587
Experience:  30 years Licensed Electrical Contractor in Illinois, Adjunct College Electrical Instructor, Former Electrical Inspector, Diploma: Digital Electronics, FCC Technician License
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I was changing a light fixture in my house and in the prosses

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I was changing a light fixture in my house and in the prosses found one wire is burnt through. I am not sure how to explain it with out a photo. But there are a grouping of black wires and a grouping of white and then the normal red and white wire and no ground visable the black wire is not connect to the main red or white and it was in the grouping of black wires. name is XXXXX XXXXX I will be happy to assist you with your electrical question. My goal is to exceed your expectations on Just Answer!


1) What is the wiring scheme of the fixture box, ie, is it wired using Romex cable or Armored cable or installed in metal conduit?


2) Where the insulation was burnt, do you still have a sufficient length of wire coming out of the box where you can splice onto using a wire nut? How short is the burnt piece?


3) What is the size of the conductor that was burnt? 14 or 12 AWG copper? What is the size (how many amps 15 or 20?) of the branch circuit breaker that controls the circuit for the burnt wire?

Customer: replied 3 years ago.
Is there any way I can send you a photo?

Hello should have a paper-clip icon on your end where you can insert a photo (jpeg file).


If not you can upload the picture at which is a free image hosting website. Once you upload the photo file, I will need you to post the URL to me in order for me to view the pic.

Customer: replied 3 years ago. here is the photo. Pardon my ignorance. I just started out taking down an old light fixture to add more light to my room now I'm in total darkness

Thanks for the URL Eric.......I can view the pic


1) I can see that the ceiling box is a metal octagon box and it appears that the box was wired in conduit. Please confirm that this box is wired using metal conduit?


2) Those wires are severely burnt and will need to be replaced. I don't think you will be able to salvage them and re-splice onto them.


3) From the pic, it also appears that the splices were just twisted together and black electricians tape was wrapped around the splices. Splicing conductors like that was performed in the old days but now per the National Electrical Code, all splices for branch circuit conductors must be spliced using a plastic wire nut.


4) Due to the arc/burnt marks on the insulation, I would recommend by labeling each wire using white electricians tape and either make a simple sketch or make sure you save a good photo of the box as-is.


You will then need someone to assist you with this. Turn the breaker to the OFF position and gently tug on 1 conductor at a time and have your assistant listen in nearby boxes where the other end of the wire terminates at. Once all of the arc'd/burnt wires are properly identified, you will need to de-install the burnt wires and pull new wires into the conduit. Make sure the new wire size corresponds to the circuit breaker, ie, for a 15 amp breaker, needs to be 14 AWG copper. For a 20 amp breaker, wire size needs to be a 12 AWG copper.


Once the new conductors are pulled, code requires approximately 6 inches of free conductor length or 3 inches of length past the face of the box. Once the new conductors are installed, then re-splice them according to color code and using plastic twist-on wire nuts at each splice.


5) With burnt marks like this, it is possible that the branch circuit may have been over-loaded thus causing the degradation of the insulation or the poor quality of the splices caused some major arcing? I would recommend to determine what loads are connected to this circuit besides just the light fixture?




Hope this helps.........If you have any additional questions, let me know and I'll be glad to answer them for you.


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


The next time you have an electrical question, you can also request for me at:



Customer: replied 3 years ago.
Thank you so much for your advise and you will be getting a top rating. My last question to you is is there any way to not have to connect the burnt/arc wire and put a nut cap on it and just install the light and turning the power back on. Or even if I leave the light can I turn the power back on?

Eric...... due to the severity of the arcing and burn marks, I would not recommend that until the conductors are replaced. Those wires are pretty bad and would be considered as a potential fire/safety hazard if re-connecting anything to them.


To play it safe, I would leave the branch circuit breaker in the OFF position since it is possible that some of those wires are feeding into other switches and/or receptacles.

Kevin and other Electrical Specialists are ready to help you

Eric..............Thank you for the Excellent Service rating...............much appreciated!


If you have any other questions, just let me know.


Take care and have a great evening..............Thanks................Kevin!

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