Current Protection - ABB REQ650 Product Manual

Breaker protection REQ650 ANSI
Product version: 1.1

4. 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.
Instantaneous phase overcurrent
protection SPTPIOC (50)
The instantaneous phase overcurrent function
for single pole tripping 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.
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.
Four step phase overcurrent
protection OC4SPTOC (51/67)
The four step phase overcurrent function for
single pole tripping (OC4SPTOC, 51_67) has an
inverse or definite time delay independent for
each step separately.
All IEC and ANSI time delayed characteristics
are available.
The directional function is voltage polarized
with memory. The function can be set to be
16
directional or non-directional independently for
each of the steps.
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 EF4PTOC (51N_67N)
The four step residual overcurrent protection
(EF4PTOC, 51N/67N) 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.
The directional function includes 3 options
• voltage polarized
• current polarized
• dual polarized
EF4PTOC (51N/67N) can be set directional or
non-directional independently for each of the
steps.
Second harmonic blocking can be set
individually for each step.
Sensitive directional residual
overcurrent and power protection
SDEPSDE (67N)
In isolated networks or in networks with high
impedance grounding, the ground fault current
1MRK 505 269-BUS -
Issued: April 2011
ABB