2. OPERATION LOGIC
GEK-106168E
DBF Breaker Failure Protection
9
Group
Status
Comment
4.0 - 4.15
5.0 -5.15
The DBF units are supplied with the following target LED’s default configuration:
LED
Nº
LEFT COLUMN
LED
Nº
RIGHT COLUMN
1
TRIP STAGE 1
9
LOW SET PICKUP
2
TRIP STAGE 2
10
50BF POLE A INIT
3
PHASE A TRIP
11
50BF POLE B INIT
4
PHASE B TRIP
12
50BF POLE C INIT
5
PHASE C TRIP
13
INT. ARC A POLE
6
3P TRIP NO I
14
INT. ARC B POLE
7
INT. ARC TRIP
15
INT. ARC C POLE
8
HIGH SET PICKUP
16
REMOTE COMMUNICATIONS
2.2.4 CIRCUIT BREAKER BREAKING CAPACITY MONITORING
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
t) on each phase. I
2
t is
expressed in kA
2
sec.
The value I
2
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
2
t OP MODE) which can be used to assign a fixed
opening time (given by another setting (kI
2
t INT TIME)). Otherwise the unit measures the time between the
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
2
t LIMIT) setting fixes the maximum life breaking capability (it is recommended
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
the I
2
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
2
t and the number of the
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.
Содержание DBF
Страница 3: ......
Страница 7: ...LIST OF FIGURES iv DBF Breaker Failure Protection GEK 106168E ...
Страница 27: ...3 SETTINGS 20 DBF Breaker Failure Protection GEK 106168E ...
Страница 31: ...4 TECHNICAL CHARACTERISTICS 24 DBF Breaker Failure Protection GEK 106168E ...
Страница 45: ...6 ACCEPTANCE TESTS 38 DBF Breaker Failure Protection GEK 106168E ...
Страница 47: ...7 INSTALLATION AND MAINTENANCE 40 DBF Breaker Failure Protection GEK 106168E ...
Страница 57: ...8 KEYBOARD AND DISPLAY 50 DBF Breaker Failure Protection GEK 106168E ...
Страница 58: ...FIGURES GEK 106168E DBF Breaker Failure Protection 51 FIGURES FIGURES FIGURES FIGURES ...
Страница 59: ...FIGURES 52 DBF Breaker Failure Protection GEK 106168E FIGURE 1 BREAKER FAILURE LOGIC 189C4114 SHEET 2 ...
Страница 60: ...FIGURES GEK 106168E DBF Breaker Failure Protection 53 FIGURE 2 EXTERNAL CONNECTIONS 189C4114 SHEET 1 ...
Страница 61: ...FIGURES 54 DBF Breaker Failure Protection GEK 106168E FIGURE 3 FRONT VIEW 226B7412 H9 ...
Страница 62: ...FIGURES GEK 106168E DBF Breaker Failure Protection 55 FIGURE 4 REAR VIEW 226B7412H10 ...
Страница 63: ...FIGURES 56 DBF Breaker Failure Protection GEK 106168E FIGURE 5 DIMENSIONS DIAGRAM 226B6086H10 ...
Страница 64: ...FIGURES GEK 106168E DBF Breaker Failure Protection 57 FIGURE 6 PANEL DRILLING 226B6086H10 ...