6 Protection Functions
P50 Agile P253
6-24
P253/EN M/C
to the relay, for example, when CB (52A) contact of CB is high. This function is deactivated when the
motor is shutdown and also during the inhibit time delay
T inhib
.
2.11
Circuit Breaker Fail Protection
When a fault occurs one or more protection devices will operate and issue a trip command to the
relevant circuit breakers. Operation of the circuit breaker is essential to isolate the fault and prevent, or
limit, damage to the power system. For transmission and sub-transmission systems slow fault
clearance can also threaten system stability.
For these reasons, it is common practise to install Circuit Breaker Failure protection (CBF). CBF
protection monitors the circuit breaker and establishes whether it has opened within a reasonable
time. If the fault current has not been interrupted following a set time delay from circuit breaker trip
initiation the CBF protection will operate. This means the upstream circuit breakers are back-tripped to
ensure that the fault is isolated.
CBF operation can also reset all start output contacts ensuring that any blocks asserted on upstream
protection are removed.
2.11.1
Circuit Breaker Fail Implementation
Circuit Breaker Failure Protection is implemented in the
CB FAIL
column of the relevant settings
group.
The circuit breaker failure protection incorporates
CB Fail Timer
. For any protection trip the
CB Fail
Timer
is started and normally reset when the circuit breaker opens to isolate the fault. If breaker
opening is not detected the CB Fail Timer times out and close an output contact assigned to breaker
fail (using the I/O assignment feature). This contact is used to back-trip upstream switchgear,
generally tripping all infeeds connected to the same busbar section.
Summary of Contents for P50 Agile P253
Page 3: ...P50 Agile P253 1 Introduction P253 EN M C 1 1 INTRODUCTION CHAPTER 1 ...
Page 4: ...1 Introduction P50 Agile P253 1 2 P253 EN M C ...
Page 11: ...SAFETY INFORMATION CHAPTER 2 ...
Page 12: ...Safety Information Pxxx 2 ...
Page 23: ...P50 Agile P253 3 Hardware Design P253 EN M C 3 1 HARDWARE DESIGN CHAPTER 3 ...
Page 24: ...3 Hardware Design P50 Agile P253253 3 2 P253 EN M C ...
Page 28: ...3 Hardware Design P50 Agile P253253 3 6 P253 EN M C E00276 Figure 2 Hardware design overview ...
Page 32: ...3 Hardware Design P50 Agile P253253 3 10 P253 EN M C ...
Page 33: ...P50 Agile P253 4 Front Panel P253 EN M C 4 1 FRONT PANEL CHAPTER 4 ...
Page 34: ...4 Front Panel P50 Agile P253 4 2 P253 EN M C ...
Page 39: ...P50 Agile P253 4 Front Panel P253 EN M C 4 7 Figure 2 USB port ...
Page 40: ...4 Front Panel P50 Agile P253 4 8 P253 EN M C ...
Page 41: ...P50 Agile P253 5 Configuration P253 EN M C 5 1 CONFIGURATION CHAPTER 5 ...
Page 42: ...5 Configuration P50 Agile P253 5 2 P253 EN M C ...
Page 154: ...5 Configuration P50 Agile P253 5 114 P253 EN M C ...
Page 155: ...P50 Agile P253 6 Protection Functions P253 EN M C 6 1 PROTECTION FUNCTIONS CHAPTER 6 ...
Page 156: ...6 Protection Functions P50 Agile P253 6 2 P253 EN M C ...
Page 182: ...7 Protection Parameter Settings P50 Agile P253 7 2 P253 EN M C ...
Page 203: ...P50 Agile P253 8 Monitoring Control P253 EN M C 8 1 MONITORING CONTROL CHAPTER 8 ...
Page 204: ...8 Monitoring Control P50 Agile P253 8 2 P253 EN M C ...
Page 222: ...8 Monitoring Control P50 Agile P253 8 20 P253 EN M C ...
Page 223: ...P50 Agile P253 9 SCADA Communications P253 EN M C 9 1 SCADA COMMUNICATIONS CHAPTER 9 ...
Page 224: ...9 SCADA Communications P50 Agile P253 9 2 P253 EN M C ...
Page 249: ...P50 Agile P253 10 Installation P253 EN M C 10 1 INSTALLATION CHAPTER 10 ...
Page 250: ...10 Installation P50 Agile P253 10 2 P253 EN M C ...
Page 260: ...11 Commissioning Instructions P50 Agile P253 11 2 P253 EN M C ...
Page 270: ...11 Commissioning Instructions P50 Agile P253 11 12 P253 EN M C ...
Page 272: ...12 Maintenance and Troubleshooting P50 Agile P253 12 2 P253 EN M C ...
Page 282: ...13 Technical Specifications P50 Agile P253 13 2 P253 EN M C ...
Page 292: ...13 Technical Specifications P50 Agile P253 13 12 P253 EN M C ...
Page 293: ...P50 Agile P253 14 Wiring Diagrams P253 EN M C 14 1 WIRING DIAGRAMS CHAPTER 14 ...
Page 294: ...14 Wiring Diagrams P50 Agile P253 14 2 P253 EN M C ...
Page 297: ......