MP-3000a Controller
106
Alarm Codes, Descriptions and Corrective Actions
NOTE: Sensors used with the controller do not require calibration. Check sensor resistance with an
ohmmeter.
•
Shutdown Alarm (Level 1 Alarm): Alarm light on display flashes and unit stops. Correct alarm
condition and acknowledge alarm before restarting.
•
Check Alarm (Level 2 Alarm): Alarm light on display flashes until alarm is acknowledged.
•
Event Log (Level 3 Alarm): Alarm is recorded in datalogger only (inspect event log).
Alarm List
Code
Description
Corrective Action
00
Supply Air Sensor Open Circuit (Check Alarm)
• Sensor circuit resistance higher than 100,000
ohms.
• Temperature below -70C (-94F)
• Indicates:
• Open circuit to left or right hand sensor
• Defective or wrong sensor
• Defective relay board
• Defective cable No. 1 or cable No. 3
• Defective controller
• Identify defective sensor (left hand or right hand)
by viewing Data menu.
• Check sensor resistance between pins 1 and 2
on plug J15 and between pins 7 and 8 on plug
J14. Resistance must be 2,000 ohms at 25C
(77F).
• Check cable No.1 and cable No.3 between the
controller and relay board.
• Check evaporator air flow.
01
Supply Air Sensor Short Circuit (Check Alarm)
• Sensor circuit resistance lower than 200 ohms.
• Temperature below 80C (176 F).
• Indicates:
• Short circuit to left or right hand sensor
• Defective or wrong sensor
• Defective relay board
• Defective cable No.1 or cable No. 3
• Defective controller
• Identify defective sensor (left hand or right hand)
by viewing Data menu.
• Check sensor resistance between pins 1 and 2
on plug J15 and between pins 7 and 8 on plug
J14. Resistance must be 2,000 ohms at 25C
(77F).
• Check cable No.1 and cable No.3 between the
controller and relay board.
02
Return Air Sensor Open Circuit (Check Alarm)
• Sensor circuit resistance higher than 100,000
ohms.
• Temperature below -70C (-94F).
• Indicates:
• Open circuit to sensor
• Defective or wrong sensor
• Defective relay board
• Defective cable No.1
• Defective controller
• Check sensor resistance between pins 3 and 4
on plug j15. Resistance must be 2,000 ohms at
25C (77F)
• Check cable No.1 between controller and relay
board.
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...