Thermo King SLXi Spectrum, Maintenance Manual

Page: 278 / 342

Structural Maintenance 12-20
Damper Motor Heater
The damper motor is equipped with a damper motor heater. The heater improves the operation of the damper motor at low
temperatures. The damper motor heater consists of a length of resistance wire wrapped around the damper motor and a thermostat
switch that is mounted on the damper motor. The switch closes when the temperature falls to -12 +/- 3 C. The switch opens when
the temperature rises to -1.0 +/- 3 C. The heater is connected to the 7K circuit and the chassis ground (CH) (8F and CL circuits
on units with TG-VI, µP-IV, µP-V or µP-VI). When the unit is operating and the temperature of the switch is below -12 C, the
resistance wire is energised. If the temperature of the switch is above -1 C (or the unit is in heat or defrost on units with TG-VI,
µP-IV, µP-V, µP-VI or SR-2), the heater is de-energised.
Damper Motor Heater – SMX Before 6/93
1. Thermostat Switch
2. Thermostat Switch Wires
3. Resistance Wire
4. Resistance Wire
5. Splice Connector
6. Thermostat Switch Wire