TechPlus ComfortAire, Service Supplement Manual

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TechPlus
s e r v i c e s u p p l e m e n t
General Unit Operation
The unit will start operating as the driver turns on the blower switch for each side
of the bus; this sends electrical power to the compressor clutch. The compressor
clutch will engage as it is turned by the bus engine, through a compressor drive
belt.
Cooling
With the blower switch turned on and the temperature selector turned
(counterclockwise) towards the (C), electrical power is sent to the electronic
thermostat and through the. H.P. Binary Switch, and the compressor clutch. The
compressor clutch will engage, through a drive belt connected to the engine. The
engine will then turn the compressor.
During engine operation, the engine compressor, evaporator fans and condenser
fans operate while the unit is in cool.
Evaporator Coil Defrost
The defrost cycle can initiate at any time the evaporator coil reaches a
temperature of 30-32 ºF. This is controlled by the electronic thermostat and will
de-energize power to the compressor clutch. When the evaporator reaches 35-
37 ºF the thermostat will kick in and energize the compressor clutch.
Unit Features
x Dash mounted driver control
x Electronic Thermostat
x Compressor
x R-134a
Protection Features
x Control circuit breakers
x High Pressure – Low Pressure Binary Switch
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APPENDIX
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