Current Protection; Instantaneous Phase Overcurrent Protection Phpioc; Four Step Phase Overcurrent Protection Oc4Ptoc; Instantaneous Residual Overcurrent Protection Efpioc - ABB RED670 Product Manual

Line differential protection RED670 ANSI
Customized
Product version: 1.2

5. Current protection

Instantaneous phase overcurrent protection PHPIOC (50)

The instantaneous three phase overcurrent function has a low
transient overreach and short tripping time to allow use as a
high set short-circuit protection function.

Four step phase overcurrent protection OC4PTOC (51/67)

The four step phase overcurrent protection function OC4PTOC
(51/67) has independent inverse time delay settings for step 1
and 4. Step 2 and 3 are always definite time delayed.
All IEC and ANSI inverse time characteristics are available
together with an optional user defined time characteristic.
The directional function is voltage polarized with memory. The
function can be set to be directional or non-directional
independently for each of the steps.
Second harmonic blocking level can be set for the function and
can be used to block each step individually
Instantaneous residual overcurrent protection EFPIOC (50N)
The Instantaneous residual overcurrent protection EFPIOC
(50N) has a low transient overreach and short tripping times to
allow the use for instantaneous ground-fault protection, with the
reach limited to less than the typical eighty percent of the line at
minimum source impedance. EFPIOC (50N) can be configured
to measure the residual current from the three-phase current
inputs or the current from a separate current input. EFPIOC
(50N) can be blocked by activating the input BLOCK.
Four step residual overcurrent protection, zero sequence and
negative sequence direction EF4PTOC (51N_67N)
The four step residual overcurrent protection EF4PTOC (51N/
67N) has an inverse or definite time delay independent for each
step separately.
All IEC and ANSI time-delayed characteristics are available
together with an optional user defined characteristic.
EF4PTOC (51N/67N) can be set directional or non-directional
independently for each of the steps.
IDir, VPol and IPol can be independently selected to be either
zero sequence or negative sequence.
Second harmonic blocking can be set individually for each step.
EF4PTOC (51N/67N) can be used as main protection for phase-
to-ground faults.
EF4PTOC (51N/67N) can also be used to provide a system
back-up for example, in the case of the primary protection
being out of service due to communication or voltage
transformer circuit failure.
ABB
Directional operation can be combined together with
corresponding communication logic in permissive or blocking
teleprotection scheme. Current reversal and weak-end infeed
functionality are available as well.
EF4PTOC (51N/67N) can be configured to measure the residual
current from the three-phase current inputs or the current from
a separate current input.
Four step negative sequence overcurrent protection NS4PTOC
(4612)
Four step negative sequence overcurrent protection (NS4PTOC,
(4612) ) has an inverse or definite time delay independent for
each step separately.
All IEC and ANSI time delayed characteristics are available
together with an optional user defined characteristic.
The directional function is voltage polarized or dual polarized.
NS4PTOC (4612) can be set directional or non-directional
independently for each of the steps.
NS4PTOC (4612) can be used as main protection for
unsymmetrical fault; phase-phase short circuits, phase-phase-
ground short circuits and single phase ground faults.
NS4PTOC (4612) can also be used to provide a system back-
up for example, in the case of the primary protection being out
of service due to communication or voltage transformer circuit
failure.
Directional operation can be combined together with
corresponding communication logic in permissive or blocking
teleprotection scheme. The same logic as for directional zero
sequence current can be used. Current reversal and weak-end
infeed functionality are available.
Sensitive directional residual overcurrent and power protection
SDEPSDE (67N)
In isolated networks or in networks with high impedance
grounding, the ground fault current is significantly smaller than
the short circuit currents. In addition to this, the magnitude of
the fault current is almost independent on the fault location in
the network. The protection can be selected to use either the
residual current or residual power component 3V0·3I0·cos j,
for operating quantity with maintained short circuit capacity.
There is also available one nondirectional 3I0 step and one 3V0
overvoltage tripping step.
No specific sensitive current input is needed.SDEPSDE can be
set as low 0.25% of IBase.
1MRK505226-BUS D
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