ABB REB650 - Four Step Residual Overcurrent Protection, Zero, Negative Sequence Direction EF4 PTOC (51 N;67 N)

Function Setting range Accuracy
Reset time, directional pickup
function
35 ms typically at 2 to 0 x I
set
-
Critical impulse time 10 ms typically at 0 to 2 x I
set
-
Impulse margin time 15 ms typically -
1)
Note: Timing accuracy only valid when 2nd harmonic blocking is turned off
7.2 Four step residual overcurrent protection, zero,
negative sequence direction EF4PTOC (51N/67N)
7.2.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Four step residual overcurrent
protection, zero or negative sequence
direction
EF4PTOC
2
IEC11000263 V1 EN
51N/67N
7.2.2 Functionality
The four step residual overcurrent protection, zero or negative sequence direction
(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.
EF4PTOC (51N/67N) can be set directional or non-directional independently for each
of the steps.
The directional part of the function can be set to operate on following combinations:
• Directional current (I3PDir) versus Polarizing voltage (V3PPol)
• Directional current (I3PDir) versus Polarizing current (I3PPol)
• Directional current (I3PDir) versus Dual polarizing (VPol+ZPol x IPol) where
ZPol = RPol + jXPol
IDir, VPol and IPol can be independently selected to be either zero sequence or
negative sequence.
1MRK 505 277-UUS C Section 7
Current protection
83
Technical Manual