I had a call on a condenser awhile ago that I was told would run for awhile, and quit. They said it had been like that for about a week. The contactor had never been tightened down on the line side. Been like that for about five years. The ends of the wires looked as though they had been hot.
Beautiful, Philadelphia, the City of Brotherly Love!
The insulation was probably left on because the guy was never paid, and figure he would throw the customer a hard one. I see all kinds of interesting RTU trickery usually after someone else just had their unit PM'ed by a guy looking for new customers and spiffs.
That's something the Teacher would do to our shop units when we went for a smoke. so we come back and have to trouble shoot it. He would also put clear tape on the contactor so it would close just not make.
I can't believe a Tech would tighten it down on the insulation. I have never seen that. I have seen a big wire trimmed down and melt.