VAMP Ltd
Overcurrent and earth-fault relay
Technical Description
VAMP 130
VM130.EN003
Vamp 24h support phone : +358 (0)40 573 6316
19
2.2.6.
Circuit-breaker failure protection CBFP (50BF)
The operation of the circuit-breaker failure protection is based
on the supervision of the operating time, from the pick-up of the
configured trip relay to the dropout of the same relay. If that
time is longer than the operating time of the CBFP stage, the
CBFP stage activates another output relay, which will remain
activated, until the primary trip relay resets.
The CBFP stage functions also in earth-fault situations, because
its function is merely based on supervision of the function of the
output relay T1.
Starts
Trips
.
.
.
tcbfpset
R2
t
&
R1
Setting
t>
CBPF
inhibit
Figure 2.2.6-1 Block diagram of the circuit-breaker failure protection
The CBFP blocking signal prevents the CBFP stage from
operating, when the output relays or any other protection
function is operated by forced control.
Parameters of the circuit-breaker failure protection
CBFP (50BF)
Parameter:
Value/unit:
CBRel
Relay to be supervised
Setting
values
t> s Operation
time
SCntr
Start counter (Start) reading
Recorded
values
TCntr
Trip counter (Trip) reading
