©2015 Siemens Protection Devices Limited
Chapter 7 Page 46 of 64
Stage 1 CBF Timer (Retrip) = 120ms
Failed CB Retrip
Operation
40
60
80
100
120
140
160
180
200
220
240
260
280
300
320
360
340
System
Fault
Relay
Operation
and CBF
Timer
Started
Main
Trip
Relay
Operation
CB's
Fails to
Trip
No Reset of
CBF elements
CBF Retrip
Operation
CBF Retrip
Trip Relay
CB Operate Time
Stage 2 CBF Timer (Backtrip) = 250ms
No Reset of
CBF elements
CBF Back trip
Operation
Backtrip
Trip Relay
Operation
Operation of all
BB CB's
Reset of
CBF elements
ms from fault
occuring
Figure 5-3 - Two Stage Circuit Breaker Fail Timing
Example of Required Settings (e.g. HV CB)
FUNCTION CONFIG>
Gn CB Fail
Enabled
SUPERVISION > CB FAIL > 50BF-1
Gn 50BF-1 Element
Enabled
Gn 50BF-1 Setting
0.2 x In
Gn 50BF-1-1 Delay
120ms
Gn 50BF-1-2 Delay
250ms
INPUT CONFIG>INPUT MATRIX>
50BF-1 Ext Trip
BIn
OUTPUT CONFIG>OUTPUT MATRIX>
50BF-1-1
BOn, Ln
50BF-1-2
BOn, Ln
OUTPUT CONFIG>BINARY OUTPUT CONFIG>
CB1 Trip Contacts
BOn
The above based on:
First Stage Backtrip (or Re-trip)
Typical Times
Trip Relay operate time
10ms
CB Tripping time
50ms
DUOBIAS-M Reset Time
30ms
Safety
Margin
30ms
Overall First Stage CBF Time Delay
120ms
Second Stage (Back Trip)
First CBF Time Delay
120ms
Trip Relay operate time
10ms
DUOBIAS-M Reset Time
30ms
CB Tripping time
50ms
Margin
50ms
Overall Second Stage CBF Time Delay
260ms
Summary of Contents for 7SR242 Duobias
Page 1: ...Answers for energy 7SR242 Duobias Transformer Protection Relay Reyrolle Protection Devices ...
Page 2: ...2 ...
Page 4: ...4 ...
Page 6: ...6 www siemens com energy ...
Page 318: ... 2015 Siemens Protection Devices Limited Chapter 7 Page 2 of 64 ...
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Page 358: ... 2015 Siemens Protection Devices Limited Chapter 7 Page 42 of 64 ...
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