ABB REG650 Technical Manual page 281

1MRK 502 034-UEN -
Technical Manual
• UZsIZsORUNsINs; Both negative and zero sequence is activated and working
in parallel in an OR-condition
• UZsIZs AND UNsINs; Both negative and zero sequence is activated and
working in series (AND-condition for operation)
• OptimZsNs; Optimum of negative and zero sequence (the function that has the
highest magnitude of measured negative and zero sequence current will be
activated)
The delta function can be activated by setting the parameter OpDUDI to On. When
selected it operates in parallel with the sequence based algorithms.
As soon as any fuse failure situation is detected, signals FuseFailDetZeroSeq,
FuseFailDetNegSeq or FuseFailDetDUDI, and the specific functionality is
released, the function will activate the output signal BLKU. The output signal
BLKZ will be activated as well if not the internal dead phase detection,
DeadLineDet1Ph, is activated at the same time. The output BLKU can be used for
blocking voltage related measuring functions (under voltage protection, synchro-
check, and so on). For blocking of impedance protection functions output BLKZ
shall be used.
If the fuse failure situation is present for more than 5 seconds and the setting
parameter SealIn is set to On it will be sealed in as long as at least one phase
voltages is below the set value USealIn<. This will keep the BLKU and BLKZ
signals activated as long as any phase voltage is below the set value USealIn<. If
all three phase voltages drop below the set value USealIn< and the setting
parameter SealIn is set to On also the output signal 3PH will be activated. The
signals 3PH, BLKU and BLKZ signals will now be active as long as any phase
voltage is below the set value USealIn<.
If SealIn is set to On fuse failure condition is stored in the non volatile memory in
the IED. At start-up (due to auxiliary power interruption or re-start due to
configuration change) the IED checks the stored value in its non volatile memory
and re-establishes the conditions present before the shut down. All phase voltages
must became above USealIn< before fuse failure is de-activated and inhibits the
block of different protection functions.
The output signal BLKU will also be active if all phase voltages have been above
the setting USealIn< for more than 60 seconds, the zero or negative sequence
voltage has been above the set value 3U0> and 3U2> for more than 5 seconds, all
phase currents are below the setting IDLD< (operate level for dead line detection)
and the circuit breaker is closed (input CBCLOSED is activated).
The input signal MCBOP is supposed to be connected via a terminal binary input
to the N.C. auxiliary contact of the miniature circuit breaker protecting the VT
secondary circuit. The MCBOP signal sets the output signals BLKU and BLKZ in
order to block all the voltage related functions when the MCB is open independent
of the setting of OpMode or OpDUDI. An additional drop-out timer of 150 ms
prolongs the presence of MCBOP signal to prevent the unwanted operation of
Secondary system supervision
Section 10
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