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Group
4.0 - 4.15
5.0 -5.15
The DBF units are supplied with the following target LED's default configuration:
LED
Nº
1
2
3
4
5
6
7
8
To supervise the breaker health, the DBF system calculates and stores, for each operation, the accumulated
values of the square of the current multiplied by the opening time of the breaker (I
2
expressed in kA
sec.
2
The value I
t is accumulated and stored independently for each phase. These values can be accessed either by
the local HMI or by the GE-LOCAL communications software.
The function has an Integration Time Selector setting (kI
opening time (given by another setting (kI
tripping signal of the main feeder protection and the change of the status contacts of the circuit breaker (52/b).
The total Breaking Current Limit (kI
to set this to the limit supplied by the manufacturer). When this threshold is reached in any phase, the system
may be configured to close an output, if the appropriate internal signal (52 A Maintenance Alarm, 52 B
Maintenance Alarm, 52 C Maintenance Alarm) is assigned to an output. In addition, the system also has a
counter for the tripping operations.
The purpose of these functions is to provide accurate data to perform the circuit breaker maintenance, based on
the actual breaking time and current values. Once this maintenance operation has been done, the values for both
2
the I
t and number of opening operations, can be reset.
In order to be able to take into account the history of the breaker, in the case where the breakers were already in
use before the installation of the relay, the system allows to set an initial value for the I
previous breaking operations. Similarly, these values can be adjusted to a given value in order to take into account
operations carried out during protection testing.
GEK-106168E
Status
LEFT COLUMN
TRIP STAGE 1
TRIP STAGE 2
PHASE A TRIP
PHASE B TRIP
PHASE C TRIP
3P TRIP NO I
INT. ARC TRIP
HIGH SET PICKUP
2.2.4 CIRCUIT BREAKER BREAKING CAPACITY MONITORING
2
t INT TIME)). Otherwise the unit measures the time between the
2
t LIMIT) setting fixes the maximum life breaking capability (it is recommended
DBF Breaker Failure Protection
Comment
LED
RIGHT COLUMN
Nº
9
LOW SET PICKUP
10
50BF POLE A INIT
11
50BF POLE B INIT
12
50BF POLE C INIT
13
INT. ARC A POLE
14
INT. ARC B POLE
15
INT. ARC C POLE
16
REMOTE COMMUNICATIONS
2
t OP MODE) which can be used to assign a fixed
2. OPERATION LOGIC
2
2
t) on each phase. I
t is
2
t and the number of the
9
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