![background image](http://html1.mh-extra.com/html/thermo-king/098916/098916_maintenance-manual_1104333048.webp)
47
Operating Instructions
Unit On/Off Switch
The unit control box has a two position toggle
switch to turn power On or Off to the unit.
•
On position. Unit will operate on Cool or
Heat depending on the controller setpoint
temperature and the container air temperature.
•
Off position. The unit will not operate.
Sequence Of Operation
Unit Start-up
A 60 second sequence start of the required loads
occurs during initial start-up of the controller. If
cooling (or heating) is required, the unit operates
in the Cool (or Heat) mode.
•
When the Unit On/Off switch is turned On,
the LED display turns on and then off.
•
The setpoint appears briefly in the LED
display.
NOTE: When the setpoint appears in the LED
display, both the Return and Supply LEDs are
lit.
•
The LED then shows the controlling air sensor
temperature.
•
The controller energizes the heater relay for 5
seconds and senses the incoming power phase
and selects the correct power phase to unit
components.
•
The evaporator fan motors start about 40
seconds after the unit is turned on.
•
Evaporator fans operate on high speed at
setpoints of -9.9 C (14.1 F) and above.
•
Evaporator fans operate on low speed at
setpoint temperatures of -10 C (14 F) and
below.
•
The compressor starts about 10 seconds later
and the liquid line solenoid energizes (opens)
if the controller calls for cooling.
•
The condenser fan then starts if the condenser
temperature requires condenser fan operation.
•
If the controller calls for heating, the electric
heaters are pulsed on and off to provide heat.
•
The controller turns on the In-range LED
when the controlling sensor temperature is
within 1.5 C (2.7 F) of the setpoint.
NOTE: Random time delays during the initial
unit start-up minimize peak current draw.
Controller Input and Output
Signals
The MP-3000a microprocessor controls all unit
functions to maintain the cargo at the proper
temperature. The controller also monitors and
records system faults and performs pretrip.
The MPC-3000a controller uses advanced
solid-state integrated circuits to monitor and
control unit functions. The controller monitors
inputs from:
•
Return Air Sensor
•
Supply Air Sensor
•
Evaporator Coil Sensor
•
Condenser Coil Sensor
•
Ambient Sensor
•
Humidity Sensor
•
USDA (Spare) Sensors 1, 2 and 3
•
Compressor Discharge Line Temperature
Sensor
•
High Pressure Cutout Switch/Discharge
Pressure Sensor
•
Low Pressure Cutout Switch/Suction Pressure
Sensor
•
Phase measuring circuits
•
Current measuring circuits
1
Unit On/Off Switch
Figure 26: Unit On/Off Switch
1
AMA307
Содержание 098916
Страница 2: ...MAGNUM TK 51122 4 MM Rev 6 02 06 Copyright 2004 Thermo King Corp Minneapolis MN USA Printed in USA...
Страница 5: ......
Страница 11: ...Table of Contents 10...
Страница 19: ...Service Guide 18...
Страница 28: ...Specifications 27 Figure 2 Physical Specifications AMA313...
Страница 41: ...Unit Description Features Options 40...
Страница 105: ...Operating Instructions 104...
Страница 155: ...Servicing The Unit 154...
Страница 187: ...Index 186...
Страница 189: ...Wiring and Schematic Diagrams Index 188...
Страница 190: ...189 Wiring Schematic...
Страница 191: ...190 Wiring Diagram Page 1 of 2...
Страница 192: ...191 Wiring Diagram Page 2 of 2...