Compressor Soft Start Control; Outdoor Fan Control - Mitsubishi Heavy Industries V Multi FDC71VNX Technical Manual

(3) Compressor soft start control

(a) Compressor protection start I
[Control condition]
Normally, the compressor operation frequency is raised in this start pattern.
[Control contents]
(i) Starts with the compressor's target frequency at A rps.
However, when the outdoor air temperature (Tho-A) is 35°C or higher during cooling/dehumidifying or the indoor
return air temperature (Thi-A) is 25°C or higher during heating, it starts at C rps.
(ii) At 30 seconds after the start of compressor, its target frequency changes to B rps and the compressor is operated for
2 - 4 minutes with its operation frequency fixed at B rps.
Model
FDC200
FDC250
(b) Compressor protection start III
[Control condition]
Number of compressor starts is only 1 counted after the power source breaker ON.
[Control contents]
Operates by selecting one of following start patterns according to the operation mode and the outdoor air temperature
(Tho-A).
(i) Low frequency operation control during cooling/dehumidifying.
[Control condition]
Upon establishing the conditions of compressor protection start III, the low frequency operation control is
performed during cooling/dehumidifying.
[Control contents]
1) Starts with the compressor's target frequency at A rps. When the outdoor air temperature (Tho-A) is 35°C or
higher, it starts at C rps.
2) At 30 seconds after the compressor start, the compressor's target frequency is changed to B rps and the
compressor's operation frequency is fixed for 10 minutes.
Model
FDC200
FDC250
(ii) Low frequency operation control during heating.
[Control condition]
When the conditions of compressor protection start III are established and one of following conditions. a) is satisfied, the
low frequncy operation control is performed during heating.
a) At 30 minutes or more after turning the power source breaker on.
[Control contents]
a) If the compressor stats with 6 hours after the power source breaker turns on, and outdoor air temperature is
lower than -2°C, unit starts by cooling mode for 3 minutes to prevent the liquid refrigerant from returning to
compressor. (model FDC200 only)
b) Starts the compressor with its target frequency at A rps. However, when the indoor return air temperature (Thi-A)
is 25°C or higher, it start at C rps.
c) At 30 seconds after the start of compressor, the compressor's target frequency is changed to B rps and the
compressor's operation frequency is fixed for 6-10 minutes.
Model
FDC200
FDC250

(4) Outdoor fan control

(a) Outdoor fan tap and fan motor speed
Model
FDC200 Cooling/Dehumidifying
FDC250 Cooling/Dehumidifying
Operation mode
Cooling/Dehumidifying
Heating
Cooling/Dehumidifying
Heating
Operation mode
Cooling/Dehumidifying
Cooling/Dehumidifying
Operation mode
Heating
Heating
Mode
➀ speed ➁ speed ➂ speed ➃ speed ➄ speed ➅ speed ➆ speed
200
Heating 200
➀ speed ➁ speed ➂ speed ➃ speed ➄ speed ➅ speed ➆ speed
200
Heating 200
A rps B rps
45 45
45 45
55 55
55 55
A B
rps rps
45 45
55 55
A B
rps rps
45 30
55 30
Fan motor tap
390 560
390 560
370 600
370 600
336
- -
'19 • PAC-T-327
C rps
25
25
30
30
C
rps
25
30
C
rps
25
30
830 870 910
830 870 910
750 850 900
820 850 910
Unit: min -1
950
950
950
950