Special Control; Startup Control - Daikin RXYQ96PYDN Service Manual

SiUS34-801A_b

7. Special Control

7.1

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. To position the four way valve, the master and slave units
simultaneously start up.
7.1.1 Startup Control in Cooling Operation
Actuator
Compressor 1
Compressor 2
Outdoor unit fan 1
Outdoor unit fan 2
Electronic expansion
valve (Main)
Electronic expansion
valve (Subcooling)
Electronic expansion
valve (Refrigerant
charge)
Four-way valve
(Heat exchanger switch)
Four-way valve (High/low
pressure gas pipe switch)
Solenoid valve (Main
bypass)
Solenoid valve (Hot gas)
Solenoid valve
(Refrigerant regulator
liquid pipe)
Solenoid valve
(Refrigerant regulator gas
vent pipe)
Solenoid valve
(Refrigerant regulator
exhaust pipe)
Solenoid valve
(Refrigerant regulator
discharge pipe)
Ending conditions
VRVIII R-410A Heat Recovery 60Hz
Elect.
Control
symbol
Symbol
REYQ REMQ
M1C M1C
— 0 Hz
M2C M2C
M1F M1F
— STEP4
M2F M2F
Y1E
EVM Y1E 0 pls
Y3E
Y2E
EVT Y3E 0 pls
Y5E
EVJ Y4E Y2E 80 pls
Y2S
20SA Y3S OFF
Y9S
20SB Y8S Y2S ON
Y5S
SVE Y6S OFF
Y10S
SVP Y4S Y5S OFF
SVL Y3S Y4S OFF
SVG Y1S Y1S OFF
SVO Y7S Y7S OFF
SVT Y6S Y8S OFF
A lapse of
60 sec.
before
startup
STEP1
52 Hz+OFF
Ta<68°F: OFF
Ta≥68°F: STEP4
1375 pls
0 pls
80 pls
OFF
ON
ON
OFF
OFF
OFF
OFF
OFF
A lapse of 15 sec.
Special Control
Startup control
STEP2
52Hz+OFF+2STEP / 20 sec.
(Until it reaches
Pc-Pe>56.55 psi)
+1step/15 sec. (When
Pc_max>313.2 psi)
-1step/15 sec. (When
Pc_max<256.5 psi)
1375 pls
0 pls
80 pls
OFF
ON
ON
OFF
OFF
OFF
OFF
OFF
• A lapse of 90 sec.
OR
• Pc - Pe>56.55 psi
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