Breaker Failure Element (50Bf) - GE F650 Instruction Manual

5.5 CONTROL ELEMENTS
Note: The Switchgear element used in the Breaker Failure element is the one configured in the Number of Switchgear
setting, inside Breaker settings at Setpoint > Protection Elements > Breaker > Breaker settings
The breaker failure element is used to determine when a trip command sent to a breaker has not been executed within a
selectable delay. Most commonly it is a failure to open from the tripped breaker. In the event of a breaker failure, the 50BF
element must issue a signal that will trip the rest of breakers connected at that time to the same busbar, and that can
provide fault current.
Comparing the current measured by the Relay with a setting level makes breaker failure detection. If after receiving a
breaker initiate signal, the current level is maintained over the set level for a time period longer than the set time, this
indicates that the breaker that has received the opening command has not been able to open and clear the fault. The relay
would issue the corresponding breaker failure signal.
F650 elements incorporate 2 levels of current and time, together with a trip without current element, and an internal arc
detection element.
The breaker failure Initiate signal is configured at Setpoint > Relay Configuration > Protection Elements. In the BRK
FAILURE INITIATE input, the user must select the desired signal for the breaker failure initiation.
The following table describes the breaker failure element settings: Setpoint > Control Elements > Breaker Failure
Table 5–83: 50BF ELEMENT SETTINGS
SETPOINT > CONTROL ELEMENTS > BREAKER FAILURE
SETTING DESCRIPTION
Function permission
Supervision (retrip) pickup level
5
Hiset pickup level
Lowset pickup level
Internal arc pickup level
Internal arc time delay
Retrip time delay
Hiset time delay
Lowset time delay
Second stage time delay
WITHOUT current element time delay
Snapshot event generation
Settings description for breaker failure element:
Function permission (Function):
Supervision or retrip pickup level (Supervision Pickup):
Hiset pickup level (Hiset Pickup):
Lowset pickup level (Loset Pickup):
Internal arc pickup level (Internal Arc Pickup):
Internal arc time delay (Internal Arc Delay):
Supervision or Retrip time delay (Supervision Delay):
High-level time delay (Hiset Delay):
Low-level time delay (Lowset Delay):
2nd step time delay (2
No current element time delay (No Current Delay):
5-104
NAME
Function
Supervision Pickup
Hiset Pickup
Lowset Pickup
Internal Arc Pickup
Internal Arc Delay
Supervision Delay
HiSet Delay
LowSet Delay
2nd Step Delay
No Current Delay
Snapshot Events
nd
Step Delay):
F650 Digital Bay Controller

5.5.6 BREAKER FAILURE ELEMENT (50BF)

DEFAULT VALUE STEP
DISABLED N/A
1.00 0.01 A
5.00 0.01 A
2.00 0.01 A
0.10 0.01 A
10.00 0.01 s
10.00 0.01 s
10.00 0.01 s
10.00 0.01 s
10.00 0.01 s
10.00 0.01 s
ENABLED N/A
This setting allows enabling and disabling the 50BF element
Supervision level pickup current threshold
High-level pickup current threshold.
Low level pickup current threshold.
Internal arc element pickup current threshold.
Time delay applied to the internal arc element
Time delay applied to the supervision or retrip element.
Time delay applied to the high level element.
Time delay applied to the low level element.
Time delay applied to the breaker failure second step.
Time delay applied to the trip without current element.
5 SETTINGS
RANGE
[DISABLED – ENABLED]
[0.05 : 160.00]
[0.05 : 160.00]
[0.05 : 160.00]
[0.05 : 160.00]
[0.00 : 900.00]
[0.00 : 900.00]
[0.00 : 900.00]
[0.00 : 900.00]
[0.00 : 900.00]
[0.00 : 900.00]
[DISABLED – ENABLED]
GEK-106310AB