Close Fail; Current Transformer Failure - Siemens 7SG11 Manual

Any Protection Element
Status Input Y
Output
relay
P/F CBF Current Setting
E/F CBF Current Setting
ENABLE
SEF CBF Current Setting
EN
*see note 1
I
ph
I
1
ef
I
sef
Table 2-14 Circuit Breaker Fail Settings
Sub-menu: Protection
Setting name
Gn P/F CB Fail Setting
Gn E/F CB Fail Setting
Gn SEF CB Fail Setting
Gn CB Fail Time Delay 1
Gn CB Fail Time Delay 2
Sub-menu: O/P Relay Config.
Setting name
Gn CB Fail 1
Gn CB Fail 2
2.5.2

Close Fail

Argus 4 and Argus 6 only
Circuit breaker close operation is also monitored. The relay checks the status of the CB at the end of each close
pulse. If the CB has not closed then the relay locks out due to CB close fail, and any sequence is terminated.
2.5.3

Current Transformer Failure

The current flowing from each of the Phase Current Transformers is monitored. If one or two of the three input
currents falls below the CT Supervision current setting for more than the CT Failure time delay then CT Failure is
raised. If all three input currents fall below the setting CT Failure is not raised.
©2013 Siemens Protection Devices Limited
Fault Trigger
Note 1:- EN, Enable input is edge triggered and level active.
IF CBF is applied then P/F & E/F & SEF must each have an
IF any CBF Current Setting = OFF (Zero) then output = 1 when enabled.
Enable/Output is Reset when all currents are OFF (Zero) or all are below setting.
Figure 2.5-1 Functional Diagram – Circuit Breaker Fail
Range (bold = default)
OFF, 0.05, 0.1 ... 1.00
OFF, 0.05, 0.1 ... 1.00
OFF, 0.005 ... 0.96
OFF, 0.00, 0.01...20.00, 20.5
...100, 101 ... 300 s
Range (bold = default)
_, 1 for each output contact
(default: _ _ _ _ _ _ _ _ _ _ _)
7SG11 Argus Technical Reference
CB Fail Time Delay 1
Circuit breaker fail 1
Event
CB Fail Time Delay 2
Circuit breaker fail 2
Event
I
current setting.
CBF
Units Notes
xIn
xIn
xIn
sec
Units Notes
CB Fail 1
CB Fail 2
P300008 Protection Functions / CBF
P20007 Page 32 of 71