Mitsubishi Electric CMB-PW202V-J, Service Handbook

Page: 59 / 114

[
VI
Control ]
- 50 -
HWE09070 GB
(2) Heating operation
*Note 1. When the outdoor unit goes into the defrost mode, defrost command is sent to WCB and indoor units. Upon reception
of the command, the indoor units will go into the defrost mode. When defrosting is completed and upon receiving the
signal that indicates the completion of defrosting, indoor units will resume the heating operation.
*Note 2. Defrost end condition: 10 or more minutes must pass after defrost operation.
or Outdoor unit piping temperature : Refer to section "-7- Defrost Operation Control" in Chapter VII in R2 service
handbook.
Heating operation
Test run mode
ON
Thermostat
ON
Defrost
operation
3-minute restart
prevention
*Note 1,2
*Note 1,2
YES
YES
YES
YES
NO
NO
NO
NO
NO
1. Indoor/outdoor unit fan control
2. Inverter frequency control
3. Indoor unit LEV fully open
4. Solenoid valve control
5. WCB solenoid valve control, 4-way valve control
6. WCB LEV control
7. WCB 4-way valve control
Normal operation
Defrost operation
4-way valve ON
During test run mode
1. Indoor unit fan operation at
Very Low speed
2. Inverter output 0Hz
3. Indoor unit LEV open to the specified position
4. Solenoid valve OFF
5. Outdoor unit fan stop
6. WCB solenoid valve control
7. WCB LEV control
8. WCB 4-way valve control
Stopping the
defrost operation
1. Indoor unit fan stop
2. Inverter defrost frequency control
3. Indoor unit LEV fully open
4. Solenoid valve control
5. Outdoor unit fan stop
6. WCB solenoid valve control
7. WCB LEV control
8. WCB 4-way valve control
4-way valve OFF
1 3
Stopping the defrost operation
Unit in the stopped state