The Trane SWT03739 High Pressure Switch is a genuine OEM safety control designed to monitor refrigerant pressure in HVAC systems. It opens the electrical circuit when pressure reaches 650 PSIG and closes at 500 PSIG, helping protect the system from excessive pressure conditions. Featuring SPST operation and 74-inch leads, this switch is used in Trane air conditioners, heat pumps, and ... https://www.partshnc.com/trane-swt03739-high-pressure-switch-650-open-psi-500-close-psi