Is Complete Ductwork Required to Start the Condensor?
The air handler, blower, is designed to blow a certain amount of air over the cooling coils which in turn converts the refrigerant back to a gas from a liquid. It can only get the correct amount of air if all the returns and supplies are installed, otherwise the blower will not function as designed and can ice up the coils. This affects the compressor operation as the transformation of the refrigerant from gas to liquid back to gas is compromised. If the outside unit has to be charged or topped off if it's a precharged unit, everything needs to be running correctly to get the right refrigerant charge in the unit.