Startup Control - Daikin VRV II-Q RQYQ8-48PY1B Service Manual

SiBE341027
2.3

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.
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. Start both the master and the slave units
simultaneously to position the four way valve.
(1) Startup Control in Cooling Operation
Inverter compressor (INV.)
(M1C)
Electronic expansion valve
(Y1E: Main)
Inverter fan
(M1F)
Indoor unit electronic
expansion valve
(Y1E)
(2) Startup Control in Heating Operation
Inverter compressor (INV.)
(M1C)
Electronic expansion valve
(Y1E: Main)
Inverter fan
(M1F)
Four way valve
(Y3S)
Function
+2 Step / 20 sec.
52 Hz
0 Hz
0 pls
+1 Step / 15 sec. (when Pc > 2.2 MPa)
Ta < 20˚C : OFF
Step 4 -1 Step / 15 sec. (when Pc < 1.8 MPa)
≥
Ta 20˚C : Step 4
Thermo. ON: Initial opening
0 pls
10 sec.
+2 Step / 20 sec.
124 Hz
52 Hz
0 Hz
Initial opening
0 pls
Step 8
Step 4
ON
OFF
10 sec.
[Ending conditions]
OR
480 pls
[Ending conditions]
OR
Detailed Control Functions
· A lapse of 130 sec.
· Tc > 48˚C
· Pe < 0.54Pa
· Pc-Pe > 0.4MPa.
Ta: Outdoor air temperature
Tc: High pressure equivalent
saturation temperature
Pc: Value detected by high
pressure sensor
Pe: Value detected by low
pressure sensor
· A lapse of 130 sec.
· Pc > 2.65MPa
· Pc-Pe > 0.4MPa.
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