Air-con magnetic starter?

Inside the Air-con magnetic starter having a reset trimmer pot(written A(R.C)) from 10 to 16,may I know:
What is the purpose of trimmer pot.,what to be adjusted?
What is the meaning of the "A(R.C)"?
10 to 16 stand for what?
What is the purpose of reset button?
Thanks!!!

it sounds like a thermal protection that can be set between 10 Amp and 16 Amp

if they are activated you have to reset them before you can use them again

to know for sure can you post a picture

Robert-Jan