The MARS model 12749 features a patented pressure-sensitive interrupter (PSI) that safely disconnects the capacitor in the event of internal pressure buildup

eliminating the need for mounting modifications or terminal adjustments

slip-free connection to damper shafts

030" aluminum frame

the 20-881 is the standard industry tool for legacy Barber Colman pneumatic units

Trane SWT1611 Limit Switch The MARS model 12749 featuresThe Trane SWT1611 Limit Switch is a critical safety component designed for precise thermal monitoring in residential and light commercial furnaces. This high limit control features a 3 inch insert to ensure accurate sensing within the supply plenum, effectively protecting the heat exchanger from damage caused by restricted airflow or blower failure. Operating as a normally closed SPST switch, the Trane SWT1611 is engineered to open the electrical