Thermo King CRR-40 119, Manual

Page: 103 / 170

MP-3000a Controller
103
Code Description Corrective Action
7 High Pressure Cutout, Check Condenser
Probe
Indicates:
• Controller is set for Moduload and start-up is
initiated on KVQ unit. Correct by turning Unit
On/Off switch OFF. Then set controller
software switch to position 1.
• Controller clears message on compressor
start-up.
• No alarm is set until Controller determines that
unit current draw is too low (alarm 37) or supply
air temperature is too high (alarm 41).
8 Running with High Supply Difference
Indicates:
• Temperature difference between the left hand
and right hand Supply sensor is too large;
even after Probe Test indicates no sensor
errors.
• Possible causes include air leak around
sensor cable, low refrigerant charge,
defective expansion valve, etc.
• Controller clears message during defrost and
when Unit On/Off switch is turned OFF.
9 High Pressure Cutout, Check Condenser
Fan
Indicates:
• Unit stops due to high pressure cutout,
condenser fan switch is in FAN AIR position
and condenser temperature is high
• Controller clears message on compressor
start-up.
• No alarm is set until Controller determines that
unit current draw is too low (alarm 37) or supply
air temperature is too high (alarm 41).
21 Total Current Too High (Alarm)
• Unit or component current draw is 25% above
expected amps for 4 minutes.
• Indicates:
• KVQ valve malfunction
• Compressor, evaporator fan motor,
condenser fan motor or heater current too
high
• Defective volt or amp meter on relay board
• Power supply voltage too low.
• Enter Manual Function Test menu and test
(operate) each component. Check volts and
amps to determine which component has high
amp draw.
• Check power supply volts.
• Check volt and ampere meter.