Hello. Question, my AC unit was serviced less than two weeks ago. The capacitor had to be replaced since the unit wouldn't start up. Ever since the contractor came out, the unit starts up with a loud buzzing noise. It takes a few seconds and then it goes back to its usual humming sound. The unit is 3 years old.
The tech replaced an old 60 10 capacitor. Didn't have the right one with him and made one out of three he had in his car.
Two days later they came out to recheck and make sure everything was fine. I had called because the noise was loud at start up. The tech installed a starter kit. It didn't help.
What could be causing the 1-2 seconds of loud noise at start up all of a sudden? It only does it if the unit has been idle for a while.
Could it be the "combination of capacitors" I have in there now? He wired them properly, second take who came the next day didn't see anything wrong with it and said that as long as he 60 are connected to the compressor and 10 to the fan it's fine.
I have the impression the motor is powered up in stages when I hear the vibration and loud sound and once it gets enough electricity it runs fine.
Thank you.

If he added refrigerant to the system and you have a flow rater or cap tube expanding device on your indoor coil it could be a overcharge condition which would flood back for a few seconds on start-up. Seen this many times. Also the combo of the capacitors might not be exactly correct causing the compressor to strain on start up. These are just guesses on my part since I am not there to test it.

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