Daikin VRV III REYQ8PY1, Service Manual

Page: 122 / 452

Si37-701 Special Control
Function 111
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. To position the four way valve, the master and slave units
simultaneously start up.
3.1.1 Startup Control in Cooling Operation
Actuator Symbol
Elect.
symbol
Control
before
startup
Startup control
REYQ REMQ
STEP1 STEP2
Compressor 1
—
M1C M1C
0 Hz 52 Hz+OFF+OFF
52Hz+OFF+OFF+2STEP / 20
sec.
(Until it reaches
Pc-Pe>0.39 MPa)
Compressor 2 M2C M2C
Compressor 3 — M3C
Outdoor unit fan 1
—
M1F M1F
STEP4
Ta<20°C: OFF
Ta
≥
20°C: STEP4
+1step/15 sec. (When
Pc_max>2.16 MPa)
-1step/15 sec. (When
Pc_max<1.77 MPa)
Outdoor unit fan 2 M2F M2F
Electronic expansion
valve (Main)
EVM
Y1E
Y3E
Y1E 0 pls 1375 pls 1375 pls
Electronic expansion
valve (Supercooling)
EVT
Y2E
Y5E
Y3E 0 pls 0 pls 0 pls
Electronic expansion
valve (Refrigerant
charge)
EVJ Y4E Y2E 80 pls 80 pls 80 pls
Four way valve
(Heat exchanger switch)
20SA
Y2S
Y9S
Y3S OFF OFF OFF
Four way valve (High/low
pressure gas pipe switch)
20SB Y8S Y2S ON ON ON
Solenoid valve (Main
bypass)
SVE
Y5S
Y10S
Y6S OFF ON ON
Solenoid valve (Hot gas) SVP Y4S Y5S OFF OFF OFF
Solenoid valve
(Refrigerant regulator
liquid pipe )
SVL Y3S Y4S OFF OFF OFF
Solenoid valve
(Refrigerant regulator gas
vent pipe)
SVG Y1S Y1S OFF OFF OFF
Solenoid valve
(Refrigerant regulator
exhaust pipe)
SVO Y7S Y7S OFF OFF OFF
Solenoid valve
(Refrigerant regulator
discharge pipe)
SVT Y6S Y8S OFF OFF OFF
Ending conditions
A lapse of
60 sec.
A lapse of 15 sec.
•
A lapse of 90 sec.
•
Pc - Pe>0.39 MPa
OR