have an APW Wyott AP express toaster, the lower switch has fried 3 times now…it will run fine with the new switch for a few month.., then 2 wires to the switch will burn up, so we have been leaving the switches on and unplugging it…been working fine for 3 months…today, the hot lead on the plug melted down taking the receptical with it, its a 120v model,15 amp…the outlet and plug end were new, and both 15 amp, no loose wires in the receptical…the any ideas??
But did you use high amperage connectors? When you stripped the wires back, did they show and heat discoloration, or where they bright. Sometimes the heat oxidation can go back over 6 inches. Did you either ohm the heaters loads to make sure there was no short or amp test after energizing to make sure it was within spec. Lastly, did you use a quality overset crimper. One that once the crimp is started, it has to be finished before it will release. Lastly, did you have the proper dies in the crimper for the style and size..
The market is flooded with cheap crimp on ends. Finding quality ones today is a challange. And yes, I learned this the hard way years ago too. But 10,000 watt metal halide sockets aren’t as cheap as a 2 pole switch.
It all comes down to tools, materials, knowledge and proper technique:
The best sources of quality tools and materials are supply houses who cater specifically to service technicians.
Knowledge and proper technique is gained through training, internship and learned experiences.
These basic things are the basis for a successful technician’s livelihood.
Any Joe Blow can buy wire terminals, wire strippers and crimpers – then replace wire terminals all day long – likely using substandard materials and substandard tools…the best way he knows how (or learned from YouTube). Proof of whether he did it right is through the test of time. If his repair didn’t last, then he obviously didn’t to it right.
Tools/materials from local hardware stores, big box home centers or auto parts places is mostly cheap stuff. Cheap stuff yields cheap results.
Based on MY experience as a technician, I think your wires are very likely the problem. However, everything that fixbear wrote should certainly be taken into account.
If you simply snipped the old, damaged terminals off and installed new ones right behind them without checking for wire degradation due to heat, oxidation or verdigris – then you’re setting it all up for a rapid failure. Any one of those conditions will cause the wire to produce heat (through resistance), which ultimately transfers to the switch terminals and into the switch. Then the switch overheats.
One notable fact to remember: Resistance causes heat. Heat causes more resistance. In control components such as your switch, that resistance will then perpetuate to a point of causing component failure.