Special Function - Mitsubishi Electric PCA Series Service Manual

10

SPECIAL FUNCTION

10-1. ROTATION FUNCTION (AND BACK-UP FUNCTION, 2ND STAGE CUT-IN FUNCTION)
10-1-1. Operation
(1) Rotation function (and Back-up function)
• Outline of functions
· Main and sub unit operate alternately according to the interval of rotation setting.
Main and sub unit should be set by refrigerant address. (Outdoor DIP switch setting)
Refrigerant address "00"
Refrigerant address "01"
· When an error occurs to one unit, another unit will start operation. (Back-up function)
• System constraint
· This function is available only by the grouping control system (INDOOR UNIT : OUTDOOR UNIT=1:1) of 2 refrigerant
groups. (Refer to Fig. 1)
· Main indoor unit should be connected for wired remote controller and the transmission line (TB5) for main and sub unit
should also be connected. (Refer to Fig. 1)
(This function cannot be set by wireless remote controller.)
· Set refrigerant address of each unit. (DIP switch on the outdoor unit···Refrigerant address 00/01)
Operation pattern
1 [Back-up function only]··· Request code number "312"
Start operation
Main
unit
Run
IC-1
Sub
unit
Stop
IC-2
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.)
Note:
· When the unit is restarted to operate after turning off the power or operation OFF status, the unit which was operating will
start operation.
· To operate the main unit, refer to "10-1-2. How to set rotation function (Back-up function, 2nd stage cut-in function)" and set
the request code No. which is not the same as the current one, then set again the former request code No.
(2) 2nd stage cut-in function
Outline of functions
· Number of operating units is determined according to the room temperature and set point.
· When room temperature reaches higher than set point, standby unit starts. (2 units operation)
· When room temperature falls below set point
System constraint
· This function is available only in rota-
tion operation and back-up function in
cooling mode.
OCH725
Main unit
Sub unit
Error occurs on main unit.
Main Sub
Abnormal condition
Run
Error occurs on main unit.
Main Sub Sub Main Main
Stop Run
Run Stop
1~28 days
4°C, standby unit stops. (1 unit operation)
−
[2nd stage cut-in function]··· Request code number "322~324"
Main
unit
IC-1
Sub
unit
IC-2
Fig. 1
OC: Outdoor unit
Sub
IC : Indoor unit
Abnormal condition
RC: Wired remote controller
Run
Room temp. ] Set point
Start operation Sub unit start operation
Run
Stop Run
31 31
Refrigerant address Refrigerant address
"00" "01"
OC-2
OC-1
Main
3(2)
unit
IC-1 IC-2
2
2
RC
Room temp. < Set point -4°C
Sub unit stop
Stop
Sub
3(2)
unit