TCO Open Error Message

Each Viper freeze barrel evaporator outlet line has a temperature cut off (TCO) sensor clipped to the copper tube. All TCO sensors are wired in series with one leg of the 24vac passing thru to power the IO board and the motor controller board. If any of the TCO sensors exceeds 120°F, that sensor opens and the series circuit becomes open and cuts off the 24vac supply to the contactor shutting down the unit refrigeration. Items to check for:

1. Hot gas solenoid leaking thru

2. Break in wiring

3. Stuck in defrost

4. Harness not plugged into motor controller board

5. Faulty TCO