MP-3000a Controller
109
Code
Description
Corrective Action
11*
Heater Current Too Low (Check Alarm)
• Occurs during Pretrip (PTI) or Function test only.
• Heater power consumption is 25% below the
expected current draw (below approximately) 3.2
amps and 3.8 amps, depending on voltage).
• Indicates:
• Defective high evaporator temperature switch
• Defective heater element or heat relay
• Defective wire connection
• Incorrect heaters or heater connections
• Enter Manual Function Test and turn heaters ON.
Make sure the heat relay energizes. Check
current draw on each phase. Current draw
should be 4.4 on each phase at 400V (5.1 amps
at 460V).
• If heat relay fails to energize, check evaporator
high temperature switch. Switch should be
closed at temperatures below 54c (130F); there
should be continuity between pins 5 and 6 in plug
J19.
• Check cable No.2 between controller and relay
board.
• Check heater resistance between H1 and H2, H2
and H3, and H1 and H3. Resistance should be
about 99 ohms on each leg.
• Check volt and ampere meter.
12**
Evaporator Fan high Speed Current Too High
(Check Alarm)
• Occurs during Pretrip (PTI) or Function test only.
• Evaporator fan power consumption is 25%
above expected current draw (above 2.0 to 3.0
amps, depending on voltage)
• Indicates:
• Defective or stuck evaporator fan motor
• Incorrect motor or motor connections
• Defective volt or amp meter on relay board
• Open evaporator door and make sure all fans
rotate freely.
• Enter Manual Function Test and start evaporator
fans on High speed. Make sure all fans start on
high speed. Check fan motor volts and amps.
• Check volt and ampere meter.
NOTE: *If both alarms 10 and 11 are activated, the alarms are caused by a large difference in
measured amps. Enter Manual Function Test menu and start HEAT. Check the amps measurement.
If necessary, check the resistance between H1 and H2, H2 and H3, and H1 and H3. resistance should
be about 99 ohms on each leg.
**See note on next page
13**
Evaporator Fan high Speed Current Too Low
(Check Alarm)
• Occurs during Pretrip (PTI), Function test or
Probe test.
• Evaporator fan power consumption is 25% below
expected current draw (below 1.5 to 2.3 amps,
depending on voltage).
• Indicates:
• Defective evaporator fan motor relay
• Defective or open fan motor internal over
temperature protection switch
• Defective volt or amp meter on relay board
• Incorrect motor or motor connections
• Open evaporator door and make sure all fans
rotate freely.
• Enter manual Function Test and start evaporator
fans on HIGH speed. Make sure all fans start on
high speed. If a motor does not start and is very
hot, wait 10 minutes for internal over temperature
switch to close.
• Check fan motor volts and amps
• Check volt and ampere meter.
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...