ECN Forum Forums General Topics of the Trade General Discussion Area FPE Panel and burnt wires...no brainer right?

Doc,
That is certainly evidence of overheating, but I doubt that the wire size itself was the problem. The type of heat damage that you have described is most likely cause by poor contact pressure in the receptacle or at its wire termination points. The heat travels down the conductor and also causes damage to the conductor insulation, but the source of the heat was in the receptacle.
Don(resqcapt19)

I guess it could be from the screws backing off over a period of time,but you do not see this with outlets that carry smaller loads.I will have to say this might be seen more in homes where it is a larger family such as 4 or 5 people using one room to do their hair or where someone is older in a home and needs that little extra warmth,and they have their favorite place to sat and no one can budge them to get some where else.
Don the next time you dry your hair with one let it run a while and then feel of the cord and the male end and see how warm it is .and that is with only one person using it ,now would that heat transfer right back up the line and if let run long enough it would heat the wires

Virgil;
might i suggest the redneck stress test for your FPE ;

tie it on to your rear bumper

I would also check the manufacturer of the baseboard heaters, if I am not mistaken, I believe FPE was manufacturing baseboard heat.

Good point Al;
ask about a recall, i say this because the burnt wire you describe sounds just like the BERKO recall deal....

Being from up north, i have to mention that saying "Electric Heat" to our utility rep's results in the same response as a roundhouse to the crotch....


[This message has been edited by sparky (edited 02-09-2001).]

Doc,
I don't have enough hair to need a blow dryer .
I still say the heat is coming from the receptacle contacts and not the wire. Your comment about feeling the temperature of the male cord end reinforces this idea. The contact pressure in the receptacle gets lower with repeated use, and this will lead to even more heat. Some of this heat is transfered to the wire and may even be hot enough to cause insulation dmage, however if it was the wire itself heating up you would also see this same heat damage at the OCPD. It takes 20 amp of load to make a #14 run at 60°C.
Don(resqcapt19)

Don's right about where and how the heat gets generated. It's at the contact point[s] of the blades to the Receptacle's terminals.

With a high load, the contacting surfaces create high heat, due to the non-solid connection. The heat then moves away from the source, by conduction, on anything which conducts heat easily that is connected to the Receptacle . Copper is a great heat sink, so it conducts the heat rather well. In turn, the heat then is convected or conducted outwards from the conductor, through the Insulation, to the colder air [or any colder object].

This situation gets worse as the Receptacle ages and becomes looser, making the contacting pressure less and less, plus smaller overall electrical conducting areas. Results are Series Resistors in line with the load from the poor contacts. The heat is generated at those points big time!

You could run 20 amps through a #14 THHN cu for a good hour or more before it even begins to feel really hot, provided it's not surrounded by a lot of other circuits. However, run a portable floor heater for 5 minutes and the cord cap is nice and toasty warm!


Scott "S.E.T."

ok I'M gonna attack this with a slide to the left and then come in at a right angle,let's say that the wire is #14 and that load is on the heater is actually around 22-23 amps ,is the wire then going to start overheating,and lets add that the wire may be a run of
50 -60 ft.
Still if the recep contacts are the problem the cord to dryer or heater would start heating at the plug end first usually it starts to heat at the gun or heater end and work back to the recep.
Scot what ever Don paid you to agree with him I'LL double and if you really sway to my side might even have a bonus for you ha ha

I'll check the brand names on the heaters...

My intentions were to replace the 105C wire with 150C... I have an industrial-electrician that says he can get me some... my supplier can't.

The feeders themselves look okay, it was my mistake when I assumed the feeder wires were giving the trouble. The connectors looked good too, all the faults occurred in the factory wiring in the channel above the element. Not the best location in the world...