Easy Wiring Question

Hello, I was hoping I could get an opinion on an issue I recently had. About 2 months ago, I got a new outside A/C unit and upstairs air handler. My old outside unit was running on a 30 amp breaker. When the company replaced the outside unit, they gave me a 25 amp breaker since that is the max the system could hold. Everything ran fine for a little under 2 months aside from some occasional clicking noise from the outside unit. A few days ago, my power was out and my main (150 amp) breaker would not go into the off position. I had to order a new breaker and the electrician pointed out that the A/C company did not use Nulux on the aluminum wires to my new 25 amp breaker. While the new main was being put in, he put Nulux on the 25 amp breaker. Everything powered up except the outside A/C unit. The tech took off the panel of the outside unit and saw burnt (smoked as the A/C tech later called it) yellow wires going to the contractor. The electrician believes it arced and overheated the main breaker. The A/C tech came out and said the bolts on the contractor were loose and caused the "smoked" wires. Somewhat unrelated was the aluminum power wire in the outside cutoff had some of its sheathing scraped off (poor install it seems). My question is this. Can this overflow of power to the contractor break/seize my main breaker? The new 25 amp breaker never tripped, only the main breaker broke. Also curious if previously overheated wires are still safe.

Hello, My boyfriend was placing a cabinet in place on our wall and was looking for a stud he hammered a nail in when suddenly a boom. We realized he hit a wire and we lost power to one side of the kitchen and dining room. He repaired the wire well we thought he did and now only two outlets are not working. He is now cutting the wall completely since he thinks he needs to replace the entire cable. Any ideas?