Daikin Aurora Series, Service Manual

Page: 58 / 333

Startup Control SiUS341802E
45 Functions and Control
4. 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.
4.1 Startup Control in Cooling
DSH: Discharge pipe superheated degree
Pc : High pressure sensor detection value
Pe : Low pressure sensor detection value
Ta : Outdoor air temperature
Refer to page 53 for Step X.
0 Hz
0 pulse
3,000 pulse (fully open)
Step 15
Pc – Pe > 0.42 MPa (60.9 psi)
DSH > 10˚C (18˚F)
Pc – Pe > 0.32 MPa (46.4 psi)
20 rps or more
OR
&
Ta < 20˚C: OFF
(68˚F)
Ta
≥
20˚C: StepX/2
(68˚F)
Frequency step up
5 sec. interval
+3step/15 sec. (Pc > 2.16 MPa (313 psi))
–3step/15 sec. (Pc < 1.77 MPa (257 psi))
Inverter compressor
(M1C)
Electronic expansion
valve (main)
(Y1E)
Inverter fan
(M1F + M2F)
Pc – Pe > 0.17 MPa (24.7 psi)
A
B
C
D
E
RXLQ72TA
RXYQ72-120TA
19
24
29
38
57
RXLQ96/120TA
RXYQ144/168TA
16.4
16.4
18
24
36
A
B
C
D
E
Frequency
(rps)