MP-3000a Controller
112
Code
Description
Corrective Action
20
Defrost Time Too Long (Check Alarm)
• Heat signal has been ON for more than 90
minutes on 60 Hz power during Defrost (120
minutes on 50 Hz power).
• Indicates:
• Low power supply voltage
• Defective heater elements
• Defective evaporator high temperature
protection switch
• Defective heat relay
• Evaporator fans running during defrost
• Evaporator sensor placed wrong
• Initiate a manual defrost and check amperage
draw and evaporator coil temperature. Evaluate
defrost performance.
• Open evaporator door and check location of
evaporator coil sensor.
NOTE: This alarm can be activated at low
voltage and very low box temperature
conditions, even under normal operating
conditions.
22
Capacity Test 1 Error (Check Alarm)
• Occurs during Pretrip (PTI) test only.
• Difference between supply and return air
temperature is too small with low speed
evaporator fans (less than approximately 4.5C [8
F])
• Return air temperature does not reach -18C (0 F)
within preset time.
• Indicates:
• Incorrect location of supply or return air sensor
• Air leakage at supply sensor cable
• Defective supply or return air sensor
• Interchanged sensor connections
• incorrect evaporator fan rotation or high speed
operation
• Incorrect refrigeration system operation
• Container/side panels defective, damaged or
leaking
• Enter Manual Function Test and start evaporator
fans on LOW speed. Then select Sensor Checks
test and operate fans 2 to 5 minutes. Check
supply, return and evaporator coil (defrost)
sensor temperatures. Sensor readings should be
the same (evaporator coil may be 0.5 C [1.0 F]
lower due to fan motor heat).
NOTE: This sensor check does not detect air
leakage around the sensor cables.
• Open evaporator door and inspect evaporator
fan rotation. Make sure fans are rotating correctly
on low speed.
• Check the sensor connections.
• Enter Manual Function Test menu. Start and
check current draw of the following components
separately and together: compressor,
compressor 100%, condenser fan and
evaporator fans (low). Check discharge and
suction pressure readings. Also check the
refrigerant charge.
NOTE: This alarm can be activated in
ambient temperatures below -10 C (14 F),
even under normal conditions.
Содержание CRR-40 119
Страница 4: ......
Страница 16: ...Safety Precautions 16...
Страница 18: ...Service Guide 18...
Страница 20: ...Model Features 20...
Страница 32: ...Specifications 32...
Страница 120: ...MP 3000a Controller 120...
Страница 160: ...Wiring and Schematic Diagrams Index 160...
Страница 161: ...161 MPC2000 Wiring Schematic...
Страница 162: ...162 MPC2000 High Voltage Wiring Diagram...
Страница 163: ...163 MPC2000 Low Voltage Wiring Diagram...
Страница 164: ...164 MPC2000 WCC Wiring Schematic...