Standby; Restart Standby; Crankcase Heater Control - Daikin RTSQ20PY1 Service Manual

Standby

3. Standby

3.1

Restart Standby

This function is used to forcedly turn OFF the thermostat for a period of 2 minutes after a compressor stops running, in
order to prevent the frequent ON-OFF operations of the compressor and equalize pressure in the refrigerant circuit.
Furthermore, the outdoor fan continues residual operation for a while to facilitate pressure equalization and prevent the
stay of refrigerant in evaporator.
Actuator
Compressor 1
Compressor 2
Compressor 3
Outdoor unit fan1
Outdoor unit fan2
Electronic expansion valve
(Main)
Electronic expansion valve
(Subcooling)
Electronic expansion valve
(Refrigerant charge)
Solenoid valve (Refrigerant
regulator gas purging pipe)
Four way valve (Heat
exchanger switch)
Solenoid valve (Refrigerant
regulator liquid pipe)
Solenoid valve (Hot gas)
Solenoid valve (Main bypass) SVE
Solenoid valve (Refrigerant
regulator discharge pipe)
Solenoid valve (Refrigerant
regulator discharge pipe)
Four way valve (High/low
pressure gas pipe switch)
Ending conditions
3.2

Crankcase Heater Control

In order to prevent the refrigerant from melting in the compressor oil in the stopped mode, this mode is used to control
the crankcase heater.
Crankcase heater
85
Elect.
Symbol
symbol
RTSQ8P
— M1C
— M2C
— M3C
Ta>30°C: STEP4
— MF1
Ta≤30°C: OFF
— MF2
EVM Y1E
EVT Y3E
EVJ Y2E
SVG Y1S
20SA Y3S
SVL Y4S
SVP Y5S
Y6S
SVO Y7S
SVT Y8S
20SB Y2S
—
Discharge pipe
temperature < 70°C
OFF
Discharge pipe
temperature > 75°C
Operation
RTSQ10•12P
OFF OFF
— OFF
—
Ta>30°C: STEP4
Ta≤30°C: OFF
—
0 pls
0 pls
80 pls
OFF
Holds
OFF
OFF
OFF
OFF
OFF
Holds
2 min.
Crankcase heater
SiBE31-801_C
RTSQ14•16P
OFF
OFF
— OFF
Ta>30°C: STEP4
Ta≤30°C: OFF
Ta>30°C: STEP4
—
Ta≤30°C: OFF
ON
Function