Kilxon 7AM Series Safety Thermostats

　　
are often used to protect motors from overheating. They are a non-latching
devices that automatically resets when the temperature falls below a preset value. The
device that failed below was in a HVAC ventilator that had been recalled due to fires.
The motor operating the vent locked-up and overheated. When the temperature of the
motor reached the threshold value of the safety thermostat, its contacts opened, which
interrupted power to the motor. When the motor cooled, the safety thermostat’s contacts
closed, and power was restored to the motor. The motor still being locked overheated.
The process repeated until the safety thermostat failed to open. This was an
insurance claim, and because the ventilator had been recalled, the manufacturer of
the ventilator agreed to pay for subrogation damages without having to go to court.