Thermo King MD-MT, Operator'S Manual

Page: 39 / 192

Unit Description
39
Three methods of Defrost initiation are available:
Microprocessor Controller TG-V:
The
Microprocessor Controller is programmed to
automatically initiate a Defrost cycle every 4
hours during pulldown until return air temperature
is in-range (between approximately 7 degrees
above and 7 degrees below setpoint).
Air Switch:
The Air Switch automatically places
the unit into Defrost when the frost accumulation
on the evaporator coil builds up to a point where
the airflow across the coil is restricted to 40% to
50% of normal.
Manual Defrost Switch:
The Manual Defrost
switch allows the operator to initiate the Defrost
cycle. For more information see the Controls and
Instruments portion of this manual.
At in-range temperatures:
• If the setpoint is at or above 15 F (-9.4 C) the
controller will initiate Defrost every 4 hours.
• If the setpoint is below 15 F (-9.4 C) (High
Speed Heat lockout) the controller will initiate
Defrost every 4 hours.
NOTE: These defrost interval settings have been
programmed at the factory. Because the
controller can be reprogrammed, settings on
individual units may vary.
Serial Number Locations
Unit:
Nameplate on the roadside of the unit inside
the top service access grille.
Engine:
Nameplate on the valve cover.
Compressor:
Nameplate on the compressor body.
Standby Motor:
Nameplate on the motor.