Belimo 01DTS 505X Sensor 340793 762 Integrating a genuine Tecumseh K90 12 Integrating a genuine Tecumseh K90 12 ensures the electrical safety circuit remains intact the kit often includes necessary wiring harness adapters and mounting hardware to facilitate a clean retrofit the "normally closed" contact is typically wired in series with the fan starter or the outside air damper actuator circuit to force a failsafe state upon detection This unit features a manual reset mechanism and a 20ft (6m) copper capillary probe filled with vapor pressure R507 to ensure rapid response times when temperatures drop near the freezing point