This figure shows the basic circuit of split type AC unit. Since the evaporator uses also electric motor to drive its blower for a cold air circulation, supply from L1 and L2 must also travel from the power source to the evaporator motor. L1 will pass through the selector switch to supply current to the selected speed of the evaporator motor. L2 is connected to the fan capacitor for starting and running (L1 is variable depending on the speed selected). From selector switch, thermostat is connected to control the holding coil of magnetic contactor (T1) and the other end is connected to L2 (T2) to complete the circuit. If pressure switches are used in the circuit or any other safety control device, it will be connected in series with the thermostat. When the thermostat closes, holding coil of magnetic contactor energizes and pulls the armature to initiate contact. Contactor delivers current to the compressor and condenser motor circuit, when thermostat opens, magnetic contactor also cuts the line.