Standby
SiUS30-1301
46
Function and Control
3. Standby
3.1
Restart Standby
Forced standby is performed to prevent frequent repetition of ON/OFF of the compressor, and to
equalize pressure in the refrigerant system.
3.2
Crankcase Heater Control
In order to prevent the refrigerant from melting in the compressor in the stop mode, this mode
controls the crankcase heater.
Parts Name
Symbol
Electric
Symbol
Actuator Function
Inverter compressor
—
M1C
0 Hz
Inverter cooling fan
—
M1F, M2F
OFF
Four-way valve (Main)
20S1
Y5S
Holding
Four-way valve (Sub)
20S2
Y7S
Holding
Electronic expansion valve (Main)
EV1
Y1E
0 pulse
Electronic expansion valve (Subcooling)
EV3
Y3E
0 pulse
Solenoid valve (Hot gas)
SVP
Y1S
OFF
Solenoid valve (Oil return of water heat exchanger)
SVE
Y2S
OFF
Solenoid valve (Receiver gas charging)
SVL
Y3S
OFF
Solenoid valve (Receiver gas discharging)
SVG
Y4S
OFF
Solenoid valve (Non-operating unit liquid pipe closing)
SVSL
Y6S
ON
Indoor unit fan (Cooling)
—
M1F, M2F
Remote controller setting
Indoor unit electronic expansion valve (Cooling)
EV
Y1E
All indoor electronic expansion valve : 0 pulse
Indoor unit fan (Heating)
—
M1F, M2F
Indoor unit control
Indoor unit electronic expansion valve (Heating)
EV
Y1E
All indoor electronic expansion valve : 0 pulse
Branch Selector unit
Holding
Ending condition
4 minutes
Crankcase heater
OFF
Crankcase heater
ON
Discharge pipe
temperature < 158˚F
Discharge pipe
temperature > 167˚F