SiBE811001EB
Outline of Functions (Outdoor unit)
CONVENI-PACK
92
3. Apply control to reduce the intermediate INJ volume for the purpose of operation with 3 units as far as
possible, even at the overheat situation.
Control EV 3 - 5 so that the target Td becomes 95°C with HP > 2.744 MPa as well as the refrige air
conditioning operation.
Releasing condition is HP < 2.548 MPa or except for refrige air conditioning operation.
Oil return control and
control of Y3E to Y5E
Judgement of cooling overload
Judgement of oil return
Y3E, Y4E, Y5E overheat avoiding control
Y3E, Y4E, Y5E wet avoiding control
Y3E_LP1 and LP2 control
Y4E, Y5E_LP1 and LP2 control
Y4E and Y5E_Overload avoiding control
Control in 1 compressor operation
• Td (Discharge gas temperature) includes
Td1(INV.), Td2(STD1) and Td3(STD2)
• Predicted Tp (Discharge port temperature)
includes Tp_1(INV.), Tp_2(STD1) and
Tp_3(STD2)
• TdSH (Discharge gas SH) includes
TdSH1(INV), TdSH2(STD1) and TdSH3(STD2)
• TpSH(Discharge port SH) includes
TpSH1(INV), TpSH2(STD1) and TpSH3(STD2)
• TgSH is intermediate SH
TgSH=Tg–f(MP)
Tg: Plate type heat exchanger outlet thermistor
MP: Intermediate pressure sensor
f(MP): Intermediate pressure equivalent
saturation temperature calculated
f(HP): High pressure equivalent saturation
temperature calculated
&
• Td – f(HP) < 15˚C
• Td < 60˚C
• TgSH < 5
&
• Td – f(HP) < 10˚C
• Td < 60˚C
• TgSH < 5
• Both the refrigeration and air conditioning operate
• Judgement is made during cooling operation, when the refrigeration and air conditioning are operating
and high pressure is high.
Overload operation is judged as being when HP > 2.744MPa and is released when HP < 2.548MPa.
• Overheat avoiding conditions
• Td > Target Td
Control at target intermediate Td = 100˚C
• Y3E, Y4E, Y5E are open.
• Opening degree of Y3E,
Y4E, Y5E are turned down.
• Opening degree of Y3E, Y4E, Y5E are turned down.
• Wet avoiding conditions
• LP1 > LP2
When oil return is judged : Target TdSH1 = 20˚C
Except for above
: Target TdSH1 = 25˚C
Y3E controlled with above
• LP1 > LP2
When oil return is judged : Target TdSH2,
Target TdSH3 = 20˚C
Except for above
: Target TdSH2,
Target TdSH3 = 25˚C
Y4E and Y5E controlled with above.
• When cooling overload is judged
Y4E and Y5E are controlled by target Td = 95˚C
• Y3E, Y4E, Y5E = 480pls
• LP1 < LP2
When oil return is judged : Target TdSH2,
Target TdSH3 = 30˚C
Except for above
: Target TdSH2,
Target TdSH3 = 25˚C
Y4E and Y5E controlled with above.
• LP1 < LP2
When oil return is judged : Target TdSH1 = 30˚C
Except for above
: Target TdSH1 = 25˚C
Y3E controlled with above
• Judgement is made during cooling operation, when the refrigeration and air conditioning
are operating. EV is turned down slightly on the low side of low pressure and oil is
returned to the compressor on the high side of low pressure.
Oil is returned twice at 40 minutes intervals for a period of from 120 to 210 seconds.
1 memory = 5 min.
Oil return operation
Oil return operation
Time
0
480
0
480
0
480
Y3E
Y4E
Y5E
