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SiUS28-902_B
Special Control
Function
17
3. Special Control
3.1
Startup Control
On activation, following control is performed to lighten load of the compressor by back liquid and
the like. Also, the position of the four-way valve is defined.
Pc: High pressure sensor detection value
Pe: Low pressure sensor detection value
3.1.1 Startup Control in Cooling
3.1.2 Startup Control in Heating
Actuator
Operation
Remarks
Compressor
Differential pressure control
Compressor operating frequency
increases by 2 step / 20 seconds until
Pc – Pe > 58 psi.
Outdoor unit fan
High pressure control
Initial fan speed is set to STEP 0.
1-step increase with Pc > 305 psi
1-step decrease with Pc < 261 psi
Four-way valve
OFF
Main electronic expansion valve (EV1)
1400 pls
Hot gas bypass valve (SVP)
ON
Receiver gas discharging valve (SVG)
OFF
Ending conditions
230 seconds
Pc – Pe > 58 psi
45 seconds
Actuator
Operation
Remarks
Compressor
Differential pressure control
Compressor operating frequency
increases by 2 step / 20 seconds until
Pc – Pe > 58 psi
Outdoor unit fan
STEP 8
Four
-
way valve
ON
Main electronic expansion valve (EV1)
180 pls
Hot gas bypass valve (SVP)
ON
Receiver gas discharging valve (SVG)
OFF
Ending conditions
145 seconds
Pc – Pe > 58 psi
15 seconds
OR
&
OR
&