Thermo King T-1000R, Maintenance Manual

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Unit Description 5-5
DEFROST
Frost will gradually build up on the evaporator coils as a result of normal operation. Periodically this frost must be melted to
prevent a loss of cooling and airflow.
Defrost is accomplished by passing hot refrigerant gas through the evaporator coil, thus melting the frost (or ice). Melted frost
drains out of the unit onto the ground through the drain tubes. The defrost damper closes during defrost to prevent warm air from
entering the cargo area. The optional electric heater strips are also energized in defrost during electric standby operation.
Defrost can be initiated at any time the evaporator coil temperature is below 5.5 C (42 F).
There are two methods of defrost initiation:
Microprocessor Controller
The Microprocessor Controller is programmed to automatically initiate timed and forced defrost cycles. It uses temperature
sensors to determine if forced defrost is required.
Manual Defrost
Manual Defrost allows the operator to initiate a defrost cycle by pressing the
D
EFROST
key. See “Initiating a Manual Defrost
Cycle.”
DAS - DATA ACQUISITION SYSTEM (OPTIONAL - EXCEPT ON T-500R/T-DAIRY)
The DAS (Data Acquisition System) monitors and records the temperatures of (up to) six additional sensors. The sensors are
independent from the microprocessor controller and are normally located in the truck box to monitor load temperatures. DAS
data can be downloaded through a serial port to an IBM
® PC compatible computer. WinTrac™ 4.0 (or higher) software is used
to view and analyze the data. Brief reports can be printed on a microprinter connected to the serial port.
ELECTRIC STANDBY (MODEL 50 UNITS ONLY)
The Electric Standby option allows the unit to be operated on either the diesel engine or external electric power.
Standard Model 50 Features
The following features are standard equipment on units equipped with Electric Standby.
Automatic Diesel/Electric Selection
The unit will automatically switch to electric operation when a power cord is connected and the standby power is switched On.
Overload Relay
The overload relay is self-resetting.
Hot Gas Heat
Hot gas heat is utilized on all units.
Automatic Phase Correction
The control system features two motor contactors. This allows correct motor rotation regardless of phase rotation on the
incoming power.
Optional Model 50 Features
The following feature is available as an option on units equipped with Electric Standby.
• Electric Heater Strips
• Water Heat
ENGINE COMPARTMENT COMPONENTS
Coolant Expansion Tank
The coolant level and temperature are monitored by the base controller. If the coolant temperature becomes too high or the
level becomes too low, an alarm will occur and the engine will shut down.
The engine must have antifreeze protection to –34 C (–30 F). Check and add coolant in the expansion tank as needed.
DANGER: High voltage AC power is present whenever the unit is operating in the Electric mode and
whenever the unit is connected to external standby power. Voltages of this magnitude can be lethal. Exercise
extreme caution when working on the unit.
CAUTION: Do not remove expansion tank cap while the coolant is hot.