Specifications

Special Control SiUS39-602
48 Function
3. Special Control
3.1 Startup Control
This startup control is used to provide the following control to reduce the compressor load
resulting from liquid return or else during compressor startup, and also determine the position of
four way valves.
3.1.1 Startup Control in Cooling Operation
Note 1. Hold : maintain the previous position before entering this operation.
Note 2. ON at starting immediately after power is on.
Note 3. SVO is open even independent outdoor unit installation.
Actuator
Pressure equalization
before start-up
Starting control
Step1 Step2
Compressor OFF 52Hz + OFF
Compressor operating frequency
increases by 2 step/20 sec. until Pc -
Pe > 58 psi
Outdoor unit fan OFF OFF
1-step/15 sec. increases with
Pc > 319 psi
1-step/15 sec. decreases with
Pc < 261 psi
Four way valve 1 OFF OFF OFF
Four way valve 2 Hold *Note 1 OFF OFF
Main motorized valve (EV1) 0 pls 1400 pls 1400 pls
Sub motorized valve (EV2) 0 pls 1400 pls 1400 pls
Sub-cooling motorized valve (EV3) 0 pls 0 pls 0 pls
Hot gas bypass valve (SVP) OFF ON ON
Oil equalization valve (SVO) OFF ON ON *Note 3
Receiver charging valve (SVL) OFF OFF OFF
Receiver discharge valve (SVG) OFF OFF OFF
Discharge pipe stop valve (SVR) Hold Hold OFF
Non-operating unit liquid pipe stop
valve (SVSL)
ON OFF OFF
High pressure gas pipe pressure
reduction valve (SVC)
Hold
*Note 2
OFF OFF
Ending conditions 1 min. 5 sec.
• 320 sec.
• Pc - Pe > 58 psi
or