Controls
COOLING
Expert self-diagnosis function
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The expert function is provided to monitor operating conditions , predict chiller information and maintain stable operation .
Predictive maintenance information
Graph 1 - Fouling of heat transfer tubes in cooling water system
Fouling factor
Concentrated indicator
8 7 6 5 4 3 2 1
8
6
4
2
Maintenance zone
Notice line
0
0 20 40 60 80 100
Cooling load factor (%)
Graph 2 - Trend of absorbent concentration
Abnormal stop zone
Maintenance zone at cooling water 27 ° C
Maintenance zone at cooling water 31 ° C
Normal line
Normal line at cooling water 31 ° C
Normal line at cooling water 27 ° C
Maintenance line
Carrier control system
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The Carrier control system surpasses other proportional only control systems available today . The digital PID ( proportional plus integral plus derivative ) control maximises unit performance by maintaining a ± 0.5 K variance in leaving chilled-water temperature from the setpoint . Proportional controls can typically only maintain a ± 1 K variance from the setpoint . The controller ’ s innovative design also incorporates the ability to start and stop the system chilled and cooling water pumps . During shutdown these pumps are sequenced to ensure a complete dilution cycle .
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The leaving chilled-water temperature is measured every five seconds and steam input is changed according to the gradient of the leaving chilled-water temperature curve . System temperatures , setpoints , and operational records are displayed along with indicator lights for the chiller and pumps .
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The Carrier control system offers its users selfdiagnostics by constantly monitoring the chiller status and will automatically shut the chiller down if a fault occurs . The cause of shutdown will be retained in the memory and can be displayed for immediate operator review . The controller ’ s memory will also retain and display the cause of the last three system fault conditions . This method of retaining fault conditions is extremely useful for maintaining an accurate record of unit performance and fault history .
1 2
Display and control board Figure 2 - Indication lights
STOP RUN
8
0 0 20 40 60 80 100
CHILLER / HEATER # 1ABS PUMP
|
Cooling load factor (%)
Graph 3 - Vacuum condition monitoring
|
7 8 9 |
# 2ABS PUMP REF PUMP PURGE PUMP
STAND BY DILUTION SAFETY CIRCUIT
|
SET
BUZZER STOP
|
BACK
REMOTE
LOCAL
|
4 |
1.0 |
10 |
CHILLER ALARM
POWER
|
OPERATION STOP
RUN
|
5 |
|
Pressure increase indicator at storage tank
0.6
0 0
Legend 1 . Storage tank 2 . Diluted solution 3 . Purge nozzle 4 . Pd cell 5 . Pressure sensor
Notice zone
Normal zone
Maintenance zone
20 |
60 |
80 |
100 |
|
Storage ratio (%) |
|
|
|
Legend |
Name |
1 . |
Operation indication light |
2 . |
Stop indication light |
3 . |
Alarm indication light |
4 . |
Remote / local select button with |
LED |
5 . |
Operation select button with LED |
6 . |
Data display |
7 . |
Stand-by indication light |
8 . |
Dilution indication light |
9 . |
Safety circuit indication light |
10 . |
Power indication light |
GL . |
Purge indication light |
43P . |
Purge pump on-off switch |
43ES . Emergency stop switch |
|
LED colour Green Orange Red Green Green 7 segment LED ( red ) Green Green Green Orange Green |
3 |
336 C A R R I E R 2 0 1 6 / 2 0 1 7