Special Function - Mitsubishi Electric PCA Series Service Manual

11

SPECIAL FUNCTION

11-1. Rotation Function (and back-up function, 2nd stage cut-in function)
This function is only available when using wired remote controller.
11-1-1. Operation
(1) Rotation function (and Back-up function)
Outline of functions
Main and sub units operate alternately according to the interval of rotation setting.
Note: Main and sub unit should be set by refrigerant address. (Outdoor DIP switch setting)
Refrigerant address 00
Refrigerant address 01
When 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 IR wireless remote controller.)
Set refrigerant address of each unit. (DIP switch on the outdoor unit
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 OFF operation, the unit which was operating will start oper-
ation.
To operate the main unit, refer to 11-1-2. 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, and set again the former request code No.
(2) 2nd stage cut-in function
Outline of functions
When the 1st unit can NOT supply with sufficient capacity for exceptionally high-demand conditions and the actual room
temperature reaches set point , the 2nd unit starts operation in conjunction with the 1st unit.
Once the actual room temperature goes down to 7.2°F [4:] below set point , the 2nd unit stops operation automatically.
( set point set temperature by R/C (remote controller) + 7.2, 10.8, 14.4°F [4, 6, 8:] (selectable))
Number of operating units is determined according to the room temperature and set point.
When room temperature becomes higher than set point, standby unit starts. (2 units operation)
When room temperature falls below set point 7.2°F [ 4:], standby unit stops. (1 unit operation)
OCH638
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
Refrigerant address 00/01)
Fig. 1
Main
unit
OC : Outdoor unit
Sub
IC : Indoor unit
Abnormal condition
RC : Wired remote controller
Run
32 32
Refrigerant address Refrigerant address
"00" "01"
OC-1 OC-2
3(2)
3(2)
IC-2
IC-1
2
2
RC
Sub
unit