OVERVIEW: H20PS(M) series pressure switch is a more advanced miniature pressure switch in the world. It is one of the electrical switches that control the circuit open or close on pressure of the controlled medium increase or decrease. It is used widely in refrigeration system, oil pump, air pump and the other industrial equipment which require to adjust the medium pressure to protect system. WORKING PRINCIPLE: The working principle of H20PS series pressure switch is: When the pressure of the controlled medium rises to a predetermined value, the snap disk will snap act to drive a set of electrical contacts by means of a transfer pin. When the pressure of the controlled medium drops below another predetermined value, the snap disk will snap to the original state, to make the contact terminal close (or open). In this way the switch function is realized. There is a slight difference between the working principle of H20PSM series pressure switch and of H20PS series pressure switch: When the pressure of the controlled medium decrease, the switch can no reset automatically. And just only as the push button is pressed, the circuit will reset to the original state. PROPERTIES AND SPECIFICATIONS: Pressure Switch 　 H20PS H20PSM Type of Reset Automatic Manual Switch Action Option and Connect Option A=Lead Wire; Normal Open B=Lead Wire; Normal Close C-Quick Connect Terminal; Normal Open D=Quick Connect Terminal; Normal Close E=Lead Wire: Single-Pole, Double-Throw F=Quick Connect Terminal; Single-Pole, Double-Throw A=close on pressure rise B=Open on pressure rise Actuation Pressure Setting 0.15Mpa～3.45Mpa 2.5Mpa～3.4Mpa Temperature Rating -35℃～+120℃ -35℃～+120℃ Electrical Rating 120/240 Vac, 375VA; 36Vac/dc,3A; 120Vac, 5.8FLA-34.8LRA; 240Vac, 2.9FLA-15LRA. 120/240 Vac, 375VA; 28Vac/dc,3A; 120Vac, 5.8FLA-34.8LRA; 240Vac, 2.9FLA-15LRA. Life at Rated Current 100,000 cycles 6,000 cycles Dielectric Withstanding Voltage Terminal to Terminal: 750Vrms Terminal to Case: 1500Vrms Terminal to Terminal: 750Vrms Terminal to Case: 1500Vrms