why do wires melt in junction box

[celtic]

Celtic,
Unless you are running more than 15 amps of each ungrounded conductor, the grounded conductor would be operating at or below its rated 90C ampacity. If this is causing the insulation to fail, then it isn't really 90C insulation.
Don

The circuits were all 20A ....for temp. ...what the draw was on the ungrounded..I dunno?

 

[iwire]

I just want to point out that the name of the thread is why do wires melt in junction box :smile:

IMO there is a large difference between melted and discolored

I have definitely seen a number of neutrals that where not as white as they once were, they may be turning yellow / brown however I have seen very few that where actually melted and those I suspect poor or corroded terminations.

 

[JohnConnolly]

Loose connections = resistance = heat.

Your toaster doesn't trip a breaker and it makes LOTS of heat.

If both hots were on the same phase and loaded, it could have contributed to the problem as the neutral would be carring twice the load it was design to...right?


Sorry. I guess this had been ansewred many time. READ first...post after.

 

[ddk2b408]

I'm with Celtic, were the two circuits on the same or opposite phases?

Which wires were stressed, all or just the white wires?

didnt check if wires were on same phase but only the hot wire was burned not any other one.

 

[ddk2b408]

thankx

thankx

not sure if wires were on same phase. and only one wire was burned...