Control Specification SiUS04-924_A
Function and Control 31
3.3.3 Four Way Valve Operation Compensation
Outline At the beginning of the operation as the four way valve is switched, the differential pressure to
activate the four way valve is acquired by having output frequency which is more than a certain
fixed frequency, for a certain fixed time.
Detail Starting Conditions
1. When starting compressor for heating
2. When the operation mode changes from heating to cooling
3. When starting compressor for defrosting
4. When starting compressor for heating after defrosting
5. When starting compressor for the first time after resetting with the power ON
6. When starting compressor after the fault of switching over cooling / heating
The lower limit of frequency keeps A Hz for B seconds with any conditions 1 through 6 above.
3.3.4 3-minute Standby
Turning on the compressor is prohibited for 3 minutes after turning it off.
(Except when defrosting.)
3.3.5 Compressor Protection Function
When turning the compressor from OFF to ON, the upper limit of frequency is set as follows. The
Compressor Protection Function is unavailable when defrosting.
Cooling Heating
A (Hz) 83
B (seconds) 70
A (Hz) 46 ~ 55
B (Hz) 65
C (Hz) 80
D (seconds) 120 ~ 500
E (seconds) 100 ~ 200
F (seconds) 470
(sec.)
Time
(R13528)
(Hz)
Frequency
C
B
DEF
A