Bc Controller Control - Mitsubishi Electric HP120TNU-A Service Handbook

[5-3 BC Controller Control ]

5-3

BC Controller Control

1. Control of SVA, SVB, and SVC
SVA, SVB, and SVC turn on or off depending on the operation mode of the branch.
SVA
Port SVB
SVC
2. Control of SVM1 snd SVM1b
SVM turns on or off depending on the operation mode.
Operation
Cooling only
mode
SVM1,1b ON
*1. Pressure differential control: The detected differential pressure (PS1 and PS3) 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
LEV3
J, JA, KA
type
LEV4
(JA and KA types
only)
KB
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 PS3) is controlle every minute so as to be within
a certain range.
*3. Can be 85 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 (TH12, TH15)
is controlled every minute so as to be within a certain range.
26
- chapter 5
Mode
Cooling Heating
ON OFF
OFF ON
ON OFF
Cooling main Heating only
Pressure dif-
ferential con- OFF
*1
trol
Cooling
Cooling only
main
3000
Liquid level
*1
control dif-
Superheat
ferential
*4
*2
control
control
41 41
Superheat Superheat
*4 *4
control control
Stopped Defrost
OFF OFF
OFF OFF
OFF OFF
Heating main Defrost
OFF ON
Heating
Heating only
main
*3 *3
85 85
Pressure dif- Pressure dif-
ferential con- ferential con-
*2 *2
trol trol
Pressure dif- Pressure dif-
ferential con- ferential con-
*2 *2
trol trol
60 60
Stopped
OFF
Defrost Stopped
3000 900
3000 41
3000 41
60 60
HWE18220_GB