Patent ID: 8001797

Claim:
A monitor and alarm system for an air conditioning unit having a suction refrigerant line and a liquid refrigerant line, comprising: a) a low pressure sensor mounted on the suction refrigerant line; b) a mid/low pressure sensor mounted on the suction refrigerant line; c) a high pressure sensor mounted on the liquid refrigerant line; d) a 12-volt back-up battery; e) a 110 V AC to 16 V AC transformer; f) a 16 V AC to 12 V DC converter board having three connection points; g) a double pole double throw (DPDT) relay; h) a terminal board having a plurality of terminals for connection to the converter board and the relay, and to a warning device and to the pressure sensors on the suction and liquid refrigerant lines; and i) wherein the back-up battery, transformer, converter board, relays and terminal board are located within an enclosure, and wherein the monitor and alarm system monitors high and low pressure of the air conditioning unit and sets off the warning device to warn of pressure problems of the air conditioning unit.