The two thin wires are the input and output wires of the pressure switch, which are connected to the coil circuit of the AC contactor.
Wiring method:
Pressure switch input connects to power supply L1, pressure switch output connects to contactor coil A1.
Contactor coil A2 connects to power supply L2.
Through the diaphragm at the bottom of the compressor to sense the air pressure in the air compressor tank or water pressure inside the small pump, when the air pressure or water pressure reaches the preset level, the pressure switch will cut off power supply of the motor to control the air compressor tank. When the air pressure or water pressure reaches the preset value, the pressure switch cuts off the power supply of the motor to control the pressure in the air compressor tank or the water pressure in the small water pump, so that it operates between the two preset pressure values.