Heating Operation Check - Mitsubishi Electric PUHY-200YMF-C Service Handbook

(5) Heating operation
1. Indoor unit fan very low speed
operations
2. Inverter output 0Hz
3. Indoor unit LEV, oil return LEV
fully closed
4. Solenoid valve OFF
5. Outdoor unit fan stop
6. BC controller solenoid valve
OFF (PURY)
7. BC controller LEV fully closed
(PURY)
Note : 1 When outdoor unit starts defrosting, it transmits defrost operations command to (BC controller and) indoor unit, and the
indoor unit starts defrosting operations.
Similarly when defrosting operation stops, indoor unit returns to heating operation after receiving defrost end command of
outdoor unit.
Note : 2 1 PUHY-(P)200·250YMF-C
Defrosting start condition : After integrated 39 minutes : P-YMF-C, 43 minutes : YMF-C of compressor operations,
Defrosting end condition
2 PURY-(P)200·250YMF-C
Defrosting start condition : After integrated 43 minutes of compressor operations, and –8˚C:P-YMF-C, –6˚C:YMF-C or
Defrosting end condition
Heating operation
Note : 1
Note : 2
Defrosting
operation
NO
4-way valve ON
Test run start
NO
NO
Thermostat ON
YES
YES 3-minute
restart
prevention
NO
1. Indoor and outdoor unit fan
control
2. Inverter frequency control
3. Indoor unit LEV, oil return LEV
control
4. Solenoid valve control
5. BC controller solenoid valve
control (PURY)
6. BC controller LEV control
(PURY)
and – 4˚C : P-YMF-C, –2˚C : YMF-C or less outdoor unit coil temperature.
: After 10 minutes : P-YMF-C, 15 minutes : YMF-C of defrosting operation or the outdoor unit
coil temperature having risen to 8˚C or more.
less outdoor unit coil temperature. (TH7)
: After 15 minutes of defrosting operation or the outdoor unit coil temperature (TH5 and TH7)
having risen to 8˚C or more.
–68–
YES
YES
1. Indoor unit fan stop
2. Inverter defrost frequency control
3. Indoor unit LEV fully opened, oil
return LEV fully closed
4. Solenoid valve control
5. Outdoor unit fan stop
6. BC controller solenoid valve control
(PURY)
7. BC controller LEV control (PURY)
Normal operations
Defrosting operations
Stop
Test run
4-way valve OFF