Special Control Si18-525B
114 Function
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.
3.1.1 Startup Control in Cooling Operation
3.1.2 Startup Control in Heating Operation
Actuator Operation Remarks
Compressor Differential pressure control
Compressor operating frequency
increases by 2 step / 20 sec until
Pc - Pe>0.4 MPa.
Outdoor unit fan High pressure control
Initial fan speed is set to STEP 0
(Ta
<
20°C), or STEP 7 (Ta≥).
Four way valve OFF
Main electronic expansion valve (EV1) 2000 pls
Subcooling electronic expansion valve
(EV2)
0 pls
Hot gas bypass valve (SVP) ON
Receiver gas discharging valve (SVG) OFF
Ending conditions
• 255 sec.
• Pc - Pe>0.4 MPa
• 75 sec
BP unit electronic expansion valve
(operating room)
0 pls
BP unit electronic expansion valve
(stopping room)
0 pls
Actuator Operation Remarks
Compressor Differential pressure control
Compressor operating frequency
increases by 2 step / 20 sec until
Pc - Pe>0.4 MPa.
Outdoor unit fan STEP8
Four way valve ON
Main electronic expansion valve (EV1) 180 pls
Subcooling electronic expansion valve
(EV2)
0 pls
Hot gas bypass valve (SVP) ON
Receiver gas discharging valve (SVG) ON
Ending conditions
• 225 sec.
• Pc - Pe>0.4 MPa
• 40 sec
BP unit electronic expansion valve
(operating room)
0 pls
BP unit electronic expansion valve
(stopping room)
0 pls
or
&
(
or
&
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