Compressor Soft Start Control - Mitsubishi Heavy Industries SRK100VNXPZSX Technical Manual

(2) Compressor start control
(a) Compressor starts upon receipt of the thermostat ON signal from the indoor unit.
(b) However, at initial start after turning the power source breaker, it may enter the standby state for maximum 30 minutes
(" PREPARATION" is displayed on the remote control) in order to prevent the oil loss in the compressor.
If the cooling/dehumidifying/heating operation is selected from the remote control when the outdoor unit is in the standby
state, " PREPARATION" is displayed for 3 seconds on the remote control.

(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.
(b) Compressor protection start III
[Control condition] Number of compressor starts is only 1 counted after the power source breaker ON.
[Control contents]
(i) Low frequency operation control during cooling/dehumidifying
[Control condition] Upon establishing the conditions of compressor protection start III, the low frequency
[Control contents]
(ii) Low frequency operation control during heating
[Control condition] When the conditions of compressor protection start III are established and one of following conditions
[Control contents]
However, when the ambient air temperature (Tho-A) is 35°C or higher during cooling/
dehumidifying or the indoor return air temperature (Th1) 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
Cooling/Dehumidifying
FDC100, 125, 140
Operates by selecting one of following start patterns according to the operation mode and the
outdoor air temperature (Tho-A).
operation control is performed during cooling/dehumidifying.
a) 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.
b) 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
FDC100, 125, 140
a) is satisfied, the low number of revolutions operation control is performed during heating.
a) At 30 minutes or more after turning the power source breaker on
a) Starts the compressor with its target frequency at A rps. However, when the indoor unit
return air temperature (Th1) is 25°C or higher, it start at C rps.
b) 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 10 minutes.
Model
FDC100, 125, 140
Operation mode
Heating
Operation mode
Cooling/Dehumidifying
Operation mode
Heating
74
- -
'17 • PAC-T-257
A rps B rps
45 45
45 45
A B
rps rps
45 45
A B
rps rps
45 45
C rps
25
25
C
rps
25
C
rps
25