Daikin VRV II RXYQ8MY1K, Service Manual

Page: 71 / 310

Special Control Si39-502A
60 Function
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
3.1.2 Startup Control in Heating Operation
Thermostat ON
Pressure equalization
control prior to startup
Startup control
STEP1 STEP2
Compressor OFF
52Hz
+OFF +OFF +2 steps/20 sec.
(until Pc - Pe>0.39MPa is achieved)
Outdoor unit fan OFF OFF
+1 step/15 sec. (when Pc>2.16MPa)
-1 step/15 sec. (when Pc<1.77MPa)
Four way valve OFF OFF OFF
Main motorized valve (EV1) 0 pls 2000 pls 2000 pls
Subcooling motorized valve
(EV2)
0 pls 0 pls 0 pls
Hot gas bypass valve
(SVP)
OFF ON ON
Receiver gas discharging
valve (SVG)
OFF OFF OFF
Non-operating unit liquid
pipe stop valve (SVSL)
ON ON ON
Ending conditions A lapse of 15 sec. A lapse of 5 sec.
•
A lapse of 320 sec.
•
Pc - Pe>0.39MPa
OR
Thermostat ON
Pressure equalization
control prior to startup
Startup control
STEP1 STEP2
Compressor OFF
52Hz
+OFF +OFF +2 steps/20 sec.
(until Pc - Pe>0.39MPa is achieved)
Outdoor unit fan STEP4 OFF STEP8
Four way valve ON ON ON
Main motorized valve (EV1) 0 pls 0 pls 0 pls or 180 pls
Subcooling motorized valve
(EV2)
0 pls 0 pls 0 pls
Hot gas bypass valve
(SVP)
OFF ON ON
Receiver gas discharging
valve (SVG)
OFF OFF OFF
Non-operating unit liquid
pipe stop valve (SVSL)
ON ON ON
Ending conditions A lapse of 15 sec. A lapse of 5 sec.
•
A lapse of 130 sec.
•
Pc>2.94MPa
OR