ABB Relion 650 Series Applications Manual page 94

Section 7
Current protection
ITrip: The steady state current that the transformer can withstand. The setting is given in % of
IBase1 or IBase2 .
Alarm1 : Heat content level for activation of the signal ALARM1. ALARM1 is set in % of the trip heat
content level.
Alarm2 : Heat content level for activation of the output signal ALARM2. ALARM2 is set in % of the
trip heat content level.
LockoutReset : Lockout release level of heat content to release the lockout signal. When the
thermal overload protection trips a lock-out signal is activated. This signal is intended to block
switching on of the protected circuit transformer as long as the transformer temperature is high.
The signal is released when the estimated heat content is below the set value. This temperature
value should be chosen below the alarm temperature.
content level.
Warning : If the calculated time to trip factor is below the setting Warning a warning signal is
activated. The setting is given in minutes.
7.4 Breaker failure protection 3-phase activation and output
CCRBRF (50BF)
7.4.1 Identification
Function description
Breaker failure protection, 3-phase
activation and output
7.4.2 Application
In the design of the fault clearance system the N-1 criterion is often used. This means that a fault
needs to be cleared even if any component in the fault clearance system is faulty. One necessary
component in the fault clearance system is the circuit breaker. It is from practical and economical
reason not feasible to duplicate the circuit breaker for the protected component. Instead a
breaker failure protection is used.
Breaker failure protection, 3-phase activation and output (CCRBRF, 50BF) will issue a back-up trip
command to adjacent circuit breakers in case of failure to trip of the "normal" circuit breaker for
the protected component. The detection of failure to break the current through the breaker is
made by means of current measurement or as detection of remaining trip signal (unconditional).
CCRBRF (50BF) can also give a re-trip. This means that a second trip signal is sent to the protected
circuit breaker. The re-trip function can be used to increase the probability of operation of the
breaker, or it can be used to avoid back-up trip of many breakers in case of mistakes during relay
maintenance and test.
88
IEC 61850
identification
CCRBRF
© Copyright 2013 ABB. All rights reserved
LockoutReset is set in % of the trip heat
IEC 60617 ANSI/IEEE C37.2
identification device number
50BF
3I>BF
SYMBOL-U V1 EN-US
1MRK 505 287-UUS B
IP14514-1 v4
M14878-1 v4
M13916-3 v5
Busbar protection REB650
Application manual