Mitsubishi Heavy Industries FDT28KXE6A Service Manual page 12

(2) Compressor control (Master unit/slave unit)
(a) Starting compressor
(i) Compressor starting order (2 compressors specification)
After turning the power on, firstly CM1 compressor starts. (In case of the combination use, it is CM01 of master
unit) And corresponding to the condition of under-dome temperature and to the required capacity of indoor units
thermostat ON, the next compressor will start sequentially, and finally maximum 4 compressors ( in case of combi-
nation use) will start simultaneously.
1) Single use
The range of frequency for each compressor corresponding to the heat load is shown in below mentioned table.
(The table shows the case that CM1 starts first. If CM2 starts first, the frequency of CM2 should be applied that
of CM1 shown in heat load zone 1 instead.)
Following tabel is shown the case that the maximum compressor frequency is 120Hz.
Heat load zone
CM1
CM2
Note (1) Value in ( ) are for the models FDC615, 680KXE6
2) Combination use
The range of frequency for each compressor corresponding to the heat load is shown in below mentioned
table. (The table shows the case that CM01 starts first. If CM11 starts first, the frequency of CM11 should be
applied that of CM01 shown in heat load zone 1 instead.)
Heat load zone
Master unit
Slave unit
Note (1) Value in ( ) are for the models FDC1180~1360KXE6
(ii) Rotation of compressor start/stop order
1) The compressors will be changed over by determinating the start/stop order in each heat load zone.
2) In case of single use, the starting order of CM1 and CM2 will be changed over on each occasion when the out-
door unit stops.
3) In case of combination use, the starting order of CM01(CM11) and CM02(CM12) will be changed over on each
occation when the master unit or slave unit stops all independently.
4) In case of combination use, the starting order of master and slave units will be changed over on each occasion
when the master unit or slave unit stops all independently.
Starting order of outdoor units
Model
FDC335~680
FDC735~1360
(Reference)
Change in number of compressors operating
1-Compressor
Note (1) Value in ( ) are for the models FDC615, 680KXE6 and FDC1180~1360KXE6
(2) After recovery of power blackout, starting order of compressor is always CM01of master unit.
0
0Hz 20~112Hz (22~92Hz)
0Hz
0
0Hz
CM01
0Hz
CM02
CM11 0Hz
CM12 0Hz
Master→Slave→Master
Starting Order of Outdoor Units Starting Order of Compressors
−
Master → Slave → Master
2-compressors
80Hz 112Hz
(60Hz) (92Hz)
-
1 2
42 (34)~120Hz
42 (34)~120Hz
0Hz
1
20~112Hz (20~92Hz) 42~112Hz (34~92Hz)
0Hz
0Hz 42~112Hz (34~92Hz)
0Hz
CM 1 → CM 2 → CM 1
CM 1 → CM 2 → CM 1
112Hz × 2
80Hz × 2
(66Hz × 2) (92Hz × 2)
10
-
2 3
42~120Hz (34~120Hz)
0Hz 42~120Hz (34~120Hz)
42~120Hz (34~120Hz)
0Hz 42~120Hz (34~120Hz)
4-compressors