All right, I have two units outside that are brand new in fact the whole HVAC system is brand new but the air conditioners haven't been used yet. We just tried to turn on the air conditioner for the first time but the outside units didn't come on. The furnace fan responded and came on, but that's it. Both units main switch outside were tuned on and from what I could see everything seemed to be in order but nothing I did could get either units to turn on. I didn't install the system and am by no means a professional. If anyone has any advice as to what I should try I would be much obliged.

Thank you so much for your time and concern

Kind regards,
Jamshid

Go outside and then have someone turn on the air conditioner at the thermostat. You should hear a click which would be your contactor pulling in. If you do not here the contactor pulling in you don't have 24 volt which means the unit cannot start. If you hear the click you have 24 volts meaning you have problems with your 220 volt to the unit. Your best bet is get whoever installed the unit to come back. If your not a professional do not try anything other than this.

Also try your breakers in the panel. They would be double breakers. Turn them off and then on again to make sure they are not tripped