Mitsubishi Electric CITY MULTI PQRY-P200YMF-B Service Handbook page 60

(2) BC controller
Fan
Solenoid valve OFF,
LEV fully closed.
Cooling-only
Note : 1 Two error modes include indoor unit side trouble, BC controller trouble, and heat source unit side trouble. In the case of
indoor unit side trouble, error stop is observed in the concerned indoor unit only, and in the cases of BC controller and heat
source unit side troubles, error stop is observed in all the indoor units, BC controller, and heat source unit.
Start
Breaker
turned on
YES
Operation
command
NO
YES
1. Operation mode judgement
(cooling-only, heating-only,
cooling/heating mixed)
2. Transmission to heat source
unit
Receiving operation mode
command from heat source unit
Error mode
NO
Operation mode
Operation mode
Heating-only
operations operations
NO
Note : 1
YES
Cooling/heating mixed
Operation mode
Cooling-main Heating-main
operations operations
–57–
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