Mitsubishi Electric PUHY-200YMF-B Service Handbook page 71

[3] Operation Flow Chart
(1) Outdoor unit
"HO" blinks on the remote
controller
Oil return LEV, SC coil LEV
(PUHY) fully closed
1. 52C
2. Inverter output
3. Outdoor fan
4. All solenoid valve
Note : 1 For about 3 minutes after turning on power source, address and group information of outdoor unit, BC, controller indoor unit,
and remote controller are retrieved by remote controller, during which "HO" blinks on and off on remote controller. In case
indoor unit is not grouped to remote controller, "HO" display on remote controller continues blinking even after 3 minutes after
turning on power source.
Note : 2 Two trouble modes included indoor unit side trouble, (BC controller trouble) and outdoor unit side trouble. In the case of indoor
unit side trouble, error stop is observed in outdoor unit only when all the indoor units are in trouble. However, if one or more
indoor units are operating normally, outdoor unit shows only LED display without undergoing stop.
Note : 3 On PUHY system, operation mode conforms to mode command by indoor unit. However, when outdoor unit is being under
cooling operation, the operation of indoor unit will be prohibited even by setting a part of indoor units under operation, or indoor
unit under stopping or fan mode to heating mode. Reversely when outdoor unit is being heating operation, the same condition
will be commenced.
On PURY system, operation mode conforms to mode command by BC controller.
Note : 4 In case BC controller issues cooling/heating mixed operation mode, outdoor unit decides operation mode of cooling-main
operation or heating-main operation.
Start
Breaker
turned on
YES
Set indoor ad-
dress No. to remote
NO
controller
NO
Operation
command
Fan
Operation
mode
OFF
0Hz
Error mode
Stop
OFF
52C ON
Operation
mode
Cooling (Cooling- Heating (Heating-
only) operations only) operations
Operation mode command to (BC controller) outdoor unit
NO
Note : 1
YES
YES
Cooling-only, Heating-only,
Cooling/heating mixed
Note : 2
YES
NO
Note : 3
Cooling/heating mixed
(only for PURY)
Note : 4
Operation
mode
Cooling-main
operations
–69–
Normal operations
Trouble observed
Stop
Error stop
Error code blinks on the
outdoor controller board
Error command to
BC controller
Error code blinks on the
remote controller
Heating-main
operations