–49–
Mode
Connection
[2] Control of BC Controller
(1)
Control of SVA, SVB and SVC
SVA, SVB and SVC are turned on and off depending on connection mode.
Cooling
Heating
Stop
Defrost
SVA
ON
OFF
OFF
OFF
SVB
OFF
ON
OFF
OFF
SVC
ON
OFF
OFF
OFF
(2)
Control of SVM1 (only FA type)
SVM1 is turned on and off corresponding to operation mode.
Operation mode
Cooling-only
Cooling-main
Heating-only
Heating-main
Stop
SVM1
ON
OFF
OFF
OFF
OFF
* Please confirm that the above parts of BC controllers are being color-coded and shown with the name plate inside
the BC controller unit.
(3)
Control of LEV
LEV opening (sj) is controlled corresponding to operation mode as follows:
(Number of pulse)
*1
*2
*3
Superheat
control
Differential
pressure control
–
Control every minute so that superheat amount detected by bypass inlet and oulet
temperatures TH12, TH15 stay in the specified range.
(FA: TH12, TH15, FB: TH22, TH25)
Control every minute so that detected differential pressure (PS1, PS3) stay in the
specified range.
60 or more pulses are sometimes detected because of rise in liquid side pressure (PS1).
Operation mode
2000
Superheat
control *1
60
Differential
Pressure control
*2
60
2000
60
60
LEV1
LEV3
LEV3a
• Liquid level
control *3
• Differential
pressure control
*2
60
Differential
Pressure control
*2
Cooling-only
Heating-only
Cooling-main
Heating-main
Stop
FA
FB
Superheat
control *1
Superheat
control *1
Superheat
control *1
