Special Control SiUS28-902_a
21 Function
3. Special Control
3.1 Startup Control
On activation, the following control is performed to lighten the load of the compressor with liquid
refrigerant located at the compressor at startup. 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>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 ⎯
Subcooling electronic expansion valve
(EV2)
0 pls ⎯
Hot gas bypass valve (SVP) ON ⎯
Receiver gas discharging valve (SVG) OFF ⎯
Ending conditions
• 230 sec.
• Pc - Pe>58 psi
• 45 sec.
Actuator Operation Remarks
Compressor Differential pressure control
Compressor operating frequency
increases by 2 step / 20 sec. until
Pc - Pe>58 psi
Outdoor unit fan STEP 8 ⎯
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) OFF ⎯
Ending conditions
• 145 sec.
• Pc - Pe>58 psi
• 15 sec.
To Next Page
Loading...
