Special Control; Startup Control - Daikin SkyAir RZR-TA Series Service Manual

Special Control

3. Special Control

3.1

Startup Control

This control is used to equalize the pressure in the suction and discharge sides of the compressor
prior to 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, etc., after startup, the following
control is made and the position of the four way valve is also determined. To position the four way
valve, the master and slave units start up simultaneously.
Pc: High pressure sensor detection value
Pe: Low pressure sensor detection value
Ta: Outdoor air temperature
3.1.1 Startup Control in Cooling
Electric Symbol
Outdoor unit
18/24
actuator
class
Compressor M1C
Outdoor fan M1F
Main electronic Y1E
expansion valve
Subcooling —
electronic
expansion valve
Four way valve Y1S
Hot gas bypass Y2S
valve
Ending conditions
110
Pressure equalization
30/36/42/48
control prior to startup
class
M1C 0 Hz
M1F STEP 7
M2F
Y1E 0 pulse
Y3E 0 pulse
Y1S Holds
— OFF
• Pc – Pe < 0.3 MPa
OR
(43.5 psi)
• A lapse of 1 to 5 min.

Startup control

STEP 1
Minimum Increases 2 steps every 20
frequency seconds from minimum
frequency until
Pc – Pe > 0.39 MPa
(56.6 psi) is achieved
Ta < 20°C (68°F): +1 step/15 sec. (when Pc >
OFF 2.16 MPa (313 psi))
Ta ≥ 20°C (68°F): –1 step/15 sec. (when Pc <
STEP 4 1.77 MPa (257 psi))
480 pulse (Fully 480 pulse (Fully open)
open)
0 pulse 0 pulse
OFF OFF
OFF OFF
A lapse of 10 sec.
OR
Part 4 Functions and Control
SiUS281811EA
STEP 2
• A lapse of 130 sec.
• Pc – Pe > 0.39 MPa
(56.6 psi)