Special Control; Startup Control - Daikin CMSQ200A7W1B Service Manual

SiBE28-805

3. Special Control

3.1

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.
In addition, 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. To position the four way valve, the master and slave units
simultaneously start up.
3.1.1 Startup Control in Cooling Operation
Compressor
Outdoor unit fan
Four way valve (20S1)
Main motorized valve (EV1)
Subcooling motorized valve
(EV2) (CMSQ250A7)
Hot gas bypass valve
(SVP)
Accumulator oil return valve
(SVO)
Injection (SVT)
(CMSQ200A7 model)
Ending conditions
3.1.2 Startup Control in Heating Operation
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
Subcooling motorized valve
(EV2) (CMSQ250A7)
Hot gas bypass valve
(SVP)
Accumulator oil return valve
(SVO)
Injection (SVT)
(CMSQ200A7 model)
Ending conditions
Function
Thermostat ON
Pressure equalization
control prior to startup
0 Hz
STEP4
Holds
0 pls
0 pls
OFF
OFF
OFF
A lapse of one minute
Thermostat ON
Pressure equalization
control prior to startup
0 Hz
STEP4
Holds
0 pls
0 pls
OFF
OFF
OFF
A lapse of one minute
Startup control
STEP1
124 Hz
52 Hz +2 steps/20 sec.
(until Pc - Pe>0.39MPa is achieved)
Ta<20°C: OFF +1 step/15 sec. (when Pc>2.16MPa)
Ta≥20°C: STEP4 -1 step/15 sec. (when Pc<1.77MPa)
OFF OFF
480 pls 480 pls
0 pls 0 pls
OFF OFF
OFF OFF
OFF OFF
A lapse of 10 sec.
OR
Startup control
STEP1
124 Hz
52 Hz +2 steps/20 sec.
(until Pc - Pe>0.39MPa is achieved)
STEP8 STEP8
ON ON
0 pls 0 pls
0 pls 0 pls
OFF OFF
OFF OFF
OFF OFF
A lapse of 10 sec. OR
Special Control
STEP2
• A lapse of 130 sec.
• Pc - Pe>0.39MPa
STEP2
• A lapse of 130 sec.
• Pc>2.70MPa
• Pc-Pe>0.39MPa
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