Mini UM S/M
Special Control
Function
37
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 (H/P model only)
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.
1-step increase with Pc>2.1 MPa
1-step decrease with Pc<1.8 MPa
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>0.4 MPa
•
45 sec
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)
OFF
Ending conditions
•
145 sec.
•
Pc - Pe>0.4 MPa
•
15 sec
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Mini UM.book Page 37 Monday, January 24, 2005 11:32 AM
