Mitsubishi Electric CITY MULTI PUHY-400YMF-B Service Handbook page 114

(3) Cooling operation
Variable capacity unit
1. Inverter output 0 Hz
2. Indoor unit LEV, SLEV,
LEV1 full closed
3. Solenoid valve OFF
4. Outdoor unit fan stop
5. 52C2 OFF
6. F = 0 after 6 minutes 52C1 OFF
Constant capacity unit
1. 52C OFF
2. Outdoor unit fan stop
3. LEV1, LEV2 full closed
4. All solenoid valves closed
Note: 1 During cooling, indoor unit fan will operate at the set notch value whether the thermostat is ON or OFF.
Note: 2 Even when the constant capacity unit is stopped, the outdoor unit fan and the solenoid valves LEV1, LEV2 are sometimes
operated.
Cooling operation
4-way valve OFF
Indoor unit fan
operations
Test run start
NO
NO
Thermostat ON
YES
YES 3-minute
restart pre-
vention
NO
Variable capacity unit
1. Inverter frequency level control
2. Indoor LEV, SLEV, LEV1 control
3. Solenoid valve control
4. Outdoor unit fan control
5. 52C1, 52C2 control
Constant
capacity unit
operation
Note: 2
Constant capacity unit
1. 52C OFF
2. Outdoor unit fan stop
3. All solenoid valves closed
4. LEV1, LEV2 full closed
–111–
Note: 1
YES
YES
Constant capacity unit
1. 52C ON
2. Outdoor unit fan control
3. Solenoid valve control
4. LEV1 control (LEV2 full closed)
Normal operations
Test run
Stop