Startup Control - Daikin RQYQ140-180PY1 Service Manual

SiBE341001
2.4

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.
(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 (Outdoor unit heat exchanger = Evaporator)
Inverter compressor (INV.)
(M1C)
Electronic expansion valve
(Y1E: Main)
Inverter fan
(M1F)
Four way valve
(Y3S)
(3) Startup Control in Heating Operation (Outdoor unit heat exchanger = Condenser)
Inverter compressor (INV.)
(M1C)
Electronic expansion valve
(Y1E: Main)
Inverter fan
(M1F)
Four way valve
(Y3S)
Function
→
+4 +7
52 Hz
0 Hz
0 pls
+1 Step / 15 sec. (when Pc > 2.16 MPa)
Ta < 20˚C : OFF
Step 4 -1 Step / 15 sec. (when Pc < 1.77 MPa)
≥
Ta 20˚C : Step 4
Thermo. ON: Initial opening
0 pls
15 sec.
→
+4 +7
52 Hz
0 Hz
Initial opening
0 pls
Step 8
Step 4
ON
OFF
15 sec.
→
+4 +7
52 Hz
0 Hz
0 pls
+1 Step / 15 sec. (when Pc > 2.16 MPa)
-1 Step / 15 sec. (when Pc < 1.77 MPa)
Step 4
OFF OFF
15 sec.
[Ending conditions]
→
+5 Step / 20 sec.
OR
1375 pls
[Ending conditions]
→
+5 Step / 20 sec.
OR
[Ending conditions]
→
+5 Step / 20 sec.
OR
1375 pls
Detailed Control Functions
· A lapse of 90 sec.
· Tc (high pressure equivalent
saturation temperature) > 48˚C
· Pc-Pe > 0.39MPa.
· A lapse of 90 sec.
· Pc-Pe > 0.39MPa.
· A lapse of 90 sec.
· Pc-Pe > 0.39MPa.
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