The Trane SWT04656 Low Pressure BZ Switch is an HVAC pressure control component designed to monitor refrigerant pressure and help protect air conditioning and refrigeration systems. It operates by sensing low-pressure conditions and controlling the electrical circuit to regulate compressor operation. This switch is used in compatible Trane HVAC equipment to support reliable system per... https://www.partshnc.com/trane-swt04656-low-pressure-bz-switch