The Baltimore Aircoil (BAC) 312178 Vibration Switch is a safety control device designed to monitor vibration levels in HVAC equipment and protect rotating components from excessive movement. It works by detecting abnormal vibration and automatically shutting down the equipment when preset limits are exceeded, helping prevent mechanical damage and costly repairs. Commonly used in cooli... https://www.partshnc.com/312178-baltimore-aircoil-bac-vibration-switch