I recently went to replace a ceiling light fixture in our great room. Upon removing the fixture, I noticed that the neutral wire insulation was brown instead of white. The plastic covering was crispy like it had been heated and cooled several times and cracked when bending the wire. The hot wire was the same. this only seemed to extend to just below the white romex covering that was still visible in the junction box.

The wires at the switch were fine and the wire run was short so I replaced it.

The problem is that I decided to replace two other fixtures on the same circuit and they had exactly the same thing. All were the same type of light.

The circuit is on a 15 amp breaker with 14-2 wiring. The wires in all switches (each fixture is on a different switch) all are fine. Its only at each fixture where the problem seems to be.

This issue has me baffled. It also could have been from the previous homeowner as the wiring job isn't top notch. This same circuit also has the fire alarm and several plug-ins on it.

Any help (or guess) at the diagnosis would be greatly appreciated.

 

The first most common curpit is overwattage at the luminaire which I have see it pretty often so like example if each bulb socket are rated for 60 watts each and someone install more light like 75 or 100 watts bulb and over the time it get more hotter than it was rated for it.

To fix this burnted conductor snip back and run a new pigtail otherwise if you have attic right above then go up there and pull it out and put a junction box and snake down new conductors or cables due the new one are rated to handle higher tempture situation.

However if you have legit alum wires in your house this will get little more tricky to deal with it.

There is couple specail methold to deal with it.

Merci.
Marc

 

This could be over-wattage, or if your house is older, 60c/140f insulation. Replace as per french277v instructions. If the light is too dim, use a cfl and save this headache/fire/shock hazard.