Special Control; Startup Control - Daikin VRV II RXYQ8MY1K Service Manual

Special Control

3.

Special Control

3.1

Startup Control

This control is used to equalize the pressure in the front and back of the compressor prior to the startup of the
compressor, thus reducing startup loads. Furthermore, the inverter is turned ON to charge the capacitor.
In addition, to avoid stresses to the compressor due to oil return or else after the startup, the following control is made
and the position of the four way valve is also determined.
3.1.1 Startup Control in Cooling Operation
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
Subcooling motorized valve
(EV2)
Hot gas bypass valve
(SVP)
Receiver gas discharging
valve (SVG)
Non-operating unit liquid
pipe stop valve (SVSL)
Ending conditions
3.1.2 Startup Control in Heating Operation
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
Subcooling motorized valve
(EV2)
Hot gas bypass valve
(SVP)
Receiver gas discharging
valve (SVG)
Non-operating unit liquid
pipe stop valve (SVSL)
Ending conditions
60
Thermostat ON
Pressure equalization
control prior to startup
OFF
OFF
OFF
0 pls
0 pls
OFF
OFF
ON
A lapse of 15 sec.
Thermostat ON
Pressure equalization
control prior to startup
OFF
STEP4
ON
0 pls
0 pls
OFF
OFF
ON
A lapse of 15 sec.

Startup control

STEP1
52Hz +2 steps/20 sec.
+OFF +OFF (until Pc - Pe>0.39MPa is achieved)
+1 step/15 sec. (when Pc>2.16MPa)
OFF
-1 step/15 sec. (when Pc<1.77MPa)
OFF OFF
2000 pls 2000 pls
0 pls 0 pls
ON ON
OFF OFF
ON ON
OR
A lapse of 5 sec.
Startup control
STEP1
52Hz +2 steps/20 sec.
+OFF +OFF (until Pc - Pe>0.39MPa is achieved)
OFF STEP8
ON ON
0 pls 0 pls or 180 pls
0 pls 0 pls
ON ON
OFF OFF
ON ON
OR
A lapse of 5 sec.
Si39-502A
STEP2
• A lapse of 320 sec.
• Pc - Pe>0.39MPa
STEP2
• A lapse of 130 sec.
• Pc>2.94MPa
Function