ABB RELION REF615R, Техническое руководство

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Table 285: Fuse failure output control
Fuse failure detection criterion Conditions and function response
Negative-sequence criterion If a fuse failure is detected based on the negative
sequence criterion, the
FUSEF_V
output is activated.
If the fuse failure detection is active for more than five
seconds and at the same time all the phase voltage
values are below the set value of the
Seal in voltage
setting with
Enable seal in turned to "True", the
function activates the
FUSE_3PH
output signal.
The
FUSEF_V
output signal is also activated if all the
phase voltages are above the
Seal in voltage setting
for more than 60 seconds and at the same time the
negative sequence voltage is above Neg Seq
voltage Lev for more than 5 seconds, all the phase
currents are below the Current dead Lin Val setting
and the circuit breaker is closed, that is
CB_CLOSED
is TRUE.
Current and voltage delta function criterion If the current and voltage delta criterion detects a
fuse failure condition, but all the voltages are not
below the
Seal in voltage setting, only the
FUSEF_V
output is activated.
If the fuse failure detection is active for more than five
seconds and at the same time all the phase voltage
values are below the set value of the
Seal in voltage
setting with
Enable seal in turned to "True", the
function activates the
FUSE_3PH
output signal.
External fuse failure detection The
MINCB_OPEN
input signal is supposed to be
connected through a protection relay binary input to
the N.C. auxiliary contact of the miniature circuit
breaker protecting the VT secondary circuit.The
MINCB_OPEN
signal sets the
FUSEF_V
output signal
to block all the voltage-related functions when MCB
is in the open state.
The
DISCON_OPEN
input signal is supposed to be
connected through a protection relay binary input to
the N.C. auxiliary contact of the line
disconnector.The
DISCON_OPEN
signal sets the
FUSEF_V
output signal to block the voltage-related
functions when the line disconnector is in the open
state.
It is recommended to always set Enable seal in to "True". This secures that
the blocked protection functions remain blocked until normal voltage
conditions are restored if the fuse failure has been active for 5 seconds,
that is, the fuse failure outputs are deactivated when the normal voltage
conditions are restored.
The activation of the
BLOCK
input deactivates both
FUSEF_V
and
FUSEF_3PH
outputs.
Section 6
1MRS240050-IB C
Supervision functions
374 REF615R
Technical Manual