Controlling Bc Controller - Mitsubishi Electric PURY-P72 Service Handbook

[ VII Control ]

[3] Controlling BC Controller

1. Control of SV A, SV
SV A, SV B, and SV
SV A
Port SV B
SV C
2. Control of SVM1
SVM turns on or off depending on the operation mode.
Operation
Cooling only
mode
SVM1 ON
*1. Pressure differential control: The detected differential pressure (PS1 and P3) is controlle every minute so
as to be within a certain range.
3. Control of LEV
LEV opening (sj) is controlled as follows depending on the operation mode.
Operation mode
LEV1
LEV2
G,GA (only GA type)
type
LEV3
GB,HB
LEV3
type
*1. Liquid level control: The liquid level detected by the liquid inlet temperature (TH11 sensor) is controlled so as to be within
a certain range.
*2. Pressure differential control: The detected differential pressure (PS1 and P3) is controlle every minute so as to be within
a certain range.
*3. Can be 110 or more due to pressure rise on the liquid side (PS1).
*4. Superheat control: The amound of superheat that is calculated on the bypass inlet and outlet temperature (G, GA,
H:TH12,TH15, GB, HB: TH12, TH15) is controlled every minute so as to be within a certain range.
4. Control of SVM2
Operation
Cooling only
mode
SVM2 OFF
*1. Pressure differential control: The detected differential pressure (PS1 and P3) is controlled every minute so as to be with-
in a certain range.
HWE0803A
B, and SV C
C turn on or off depending on the operation mode of the branch.
Cooling Heating
ON OFF
OFF ON
ON OFF
Cooling main Heating only
Pressure dif-
ferential con- OFF
*1
trol
Cooling
Cooling only
main
2000
Liquid level
control
ferential
control
Superheat
*4
control
Superheat Superheat
*4
control control
Cooling main Heating only
Pressure differ-
OFF
ential control
Mode
Stopped Defrost
OFF OFF
OFF OFF
OFF OFF
Heating main Defrost
OFF ON
Heating
Heating only
main
110 110
*1
dif-
Pressure dif- Pressure dif-
*2
ferential con- ferential con-
*2 *2
trol trol
60 60
*4
Heating main
Pressure differ-
*1 *1
ential control
- 145 -
Stopped
OFF
Defrost Stopped
*3
2000 1200
G:1000
GA:2000
60
Defrost Stopped
OFF OFF
60
60
GB