Special Function - Mitsubishi Electric PLA-A12BA Service Manual

11

SPECIAL FUNCTION

11-1. ROTATION FUNCTION(AND BACK-UP FUNCTION, 2ND STAGE CUT-IN FUNCTION)
11-1-1. Operation
(1) Rotation function(and Back-up function)
Outline of functions
· Operating the unit of main and sub alternately according to the interval setting. (Rotation function)
The setting of main/sub unit depends on the refrigerant address.(The setting of dip switch on the outdoor unit)
Refrigerant address"00"
Refrigerant address"01"
· If an error occurrs to one unit, the other unit starts.(Back-up function)
System constraint
· This function is available only by the grouping control system(INDOOR UNIT : OUTDOOR UNIT=1:1) of 2 refrigerant
group.(Refer to Fig 1)
· It is necessary to connect remote controller crossover wiring to between units(Wireless remote controller is unusable) and
to assign refrigerant address to each unit.(Dip switch on the outdoor unit...Refrigerant address 00/01)
Operation pattern
[Back-up function only]··· Request code number "312"
Start operation
Main
unit
Run
IC-1
Sub
unit
Stop
IC-2
[Rotation function] & [Back-up function]··· Request code number "313~318"
Start operation
Main
unit
Run
IC-1
Sub
unit
Stop
IC-2
1~28 days
(Ex:When the request code number is "313", each unit operates alternately in daily cycle.)
(2) 2nd stage cut-in function
Outline of functions
· Quantity of operating units is controlled according to the room temperature and set point.
· When room temperature becomes more than set point, standby unit starts.(2 units running )
· When room temperature falls below set point -4 (7.5°F), standby unit stops.(1 unit running)
System constraint
· This function is available only in rotation operation(or back-up) and cooling mode.
[2nd stage cut-in function]··· Request code number "322~324"
Start operation
Main
unit
Run
Sub
unit
Stop
Main unit
Sub unit
Error occurred on main unit
Main Sub
Abnormal condition
Run
Error occurred on main unit
Main Sub Main Sub Main
Stop Run
Run Stop
1~28 days
Room temp. Set point Room temp. < Set point -4
Sub unit start operation Sub unit stop
Run
Fig 1
Main
unit
OC: Outdoor unit
Sub
IC:
Abnormal condition
RC: Wired remote controller
Run
(7.5 )
Stop
31 31
Refrigerant address Refrigerant address
"00" "01"
OC-1 OC-2
3(2)
3(2)
IC-2
IC-1
2
2
RC
Indoor unit
Sub
unit