Startup Control; Cooling Startup Control - Daikin RXQ12AHR Service Manual

Startup Control

4. Startup Control
Before starting the compressor:
 The capacitor is charged in the DC circuit of the inverter circuit, and
 "Pre-pressure equalization" is performed to reducing the starting current of the compressor.
Pc: High pressure sensor detection value
Pe: Low pressure sensor detection value
Ta: Outdoor air temperature
Te: Low pressure equivalent saturation temperature
4.1

Cooling Startup Control

82
Thermostat
DC circuit
capacitors
Fan motor(s)
M1F: RXQ6-12A
M1F + M2F: RXQ14-20A
Solenoid valve
Inverter compressor 1
0 Hz
(M1C)
Inverter compressor 2 0 Hz
(M2C)
∗ RXQ16-20A only
0 pulse
Electronic expansion
valve (Injection)
(Y2E)
Step4
Inverter fan
M1F: RXQ6-12A
M1F + M2F: RXQ14-20A
ON
OFF
signal
Approx. 550 V
0 V
OFF
ON
OFF
oil return
Frequency step up
5 sec. interval
Ta < 20˚C: OFF +1step/15 sec. (Pc > 2.16 MPa)
Ta ≥ 20˚C: Step4
–1step/15 sec. (Pc < 1.77 MPa)
Pc – Pe > 0.21 MPa
SiAF341904E
120 seconds
Step 4
Te < 10˚C
&
Te < Th2(∗) – 10
∗ Th2 in "Pre-pressure
equalization"
Part 4 Functions and Control