Daikin VRV S RXQ4/5ARV1, Service Manual

Page: 66 / 377

Control for 4/5/10/12 HP Outdoor Unit SiAF332111E
60 Part 4 Functions and Control
1.3 Special Control
1.3.1 Startup Control
This control is used to equalize the pressure in the suction and discharge sides of the
compressor prior to the compressor startup, 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.
Pc : High pressure sensor detection value
Pe : Low pressure sensor detection value
Ta : Outdoor air temperature
Startup Control in Cooling Operation
Outdoor Unit
Actuator
Electric symbol
Pressure equalization
control prior to startup
Startup control
RXQ4ARV1 RXQ5ARV1
RXMQ
10/12ARY1
STEP 1 STEP 2
Compressor
M1C M1C M1C
0 Hz Minimum
frequency
Increases 2 steps every
20 seconds from
minimum frequency until
Pc – Pe >
0.39 MPa is achieved
Outdoor fan
M1F M1F
M1F
M2F
4/5 HP: OFF
10/12 HP: STEP 7
Ta < 20°C: OFF
Ta

20°C: STEP 4
+1 step/15 seconds
(when Pc > 2.16 MPa)
–1 step/15 seconds
(when Pc < 1.77 MPa)
Electronic
expansion
valve (Main)
— Y1E Y1E
0 pulse Fully open Fully open
Electronic
expansion
valve
(Injection)
— — Y2E
0 pulse 0 pulse 0 pulse
Hot gas
bypass valve
Y2S — —
OFF OFF OFF
Ending conditions A lapse of 10
seconds
•
Pc – Pe <
0.3 MPa
•
A lapse of 1 to
5 minutes
OR
•
A lapse of
130 seconds
•
Pc – Pe >
0.39 MPa
OR