MP-3000a Controller
111
Code
Description
Corrective Action
17*
Condenser Fan Current Too Low (Check Alarm)
• Occurs during Pretrip (PTI) or Function test only.
• Condenser fan power consumption is 25% below
expected current draw (below 0.5 to 0.7 amps,
depending on voltage).
• Indicates:
• Defective condenser fan motor relay
• Defective or open fan motor internal over
temperature protection switch
• Defective volt or amp meter on relay board.
• Enter Manual Function Test and start condenser
fan. Make sure the fan starts. Check fan motor
volts and amps.
• Check power supply volts and amps.
• Check volt and ampere meter.
18
Power Supply Phase Error (Alarm)
• One or more frequency inputs are missing for
more than 20 seconds.
• Indicates:
• One phase on power line is missing
• Defective fuse on relay board
• Defective digital inputs on relay board
• Defective controller
• Enter Data menu and view voltage reading on
each phase.
• Check all fuses. Check cable No.1 on relay
board.
• Check cable No.1 between controller and relay
board.
• Replace relay board. Check voltage reading on
each phase.
NOTE: * If both alarms 16 and 17 are activated, the alarms are caused by a large difference in
measured amps. Enter Manual Function Test menu and start condenser fan. Check the condenser
fan amps measurement. If necessary, check the resistance in the motor between CF1 and CF2, CF2
and CF3, and CF1 and CF3. Resistance readings should be equal (approximately 25 Ohms).
19
Temperature Too Far from Setpoint (Check
Alarm)
• After 75 minutes of operation, supply or return air
temperature is not in-range and does not
approach setpoint within preset pulldown rate.
• Indicates:
• Ice or frost on evaporator coil
• Low refrigerant charge
• Air exchange vent open too much
• Container air leakage (doors open)
• Press SUP/RET key to check supply and return
air sensor temperatures. COmpare temperatures
to evaluate unit cooling capacity and
performance.Temperature difference should be
4 C to 6 C.
• Open evaporator door. Inspect coil for rice or
frost and initiate manual defrost if necessary.
• Check refrigerant charge
NOTE: This alarm can be activated if the
supply or return air temperature varies, even
if the mean temperature does approach
setpoint.
Summary of Contents for CRR-40 119
Page 4: ......
Page 16: ...Safety Precautions 16...
Page 18: ...Service Guide 18...
Page 20: ...Model Features 20...
Page 32: ...Specifications 32...
Page 120: ...MP 3000a Controller 120...
Page 160: ...Wiring and Schematic Diagrams Index 160...
Page 161: ...161 MPC2000 Wiring Schematic...
Page 162: ...162 MPC2000 High Voltage Wiring Diagram...
Page 163: ...163 MPC2000 Low Voltage Wiring Diagram...
Page 164: ...164 MPC2000 WCC Wiring Schematic...