Connection Examples For High Impedance Differential Protection; Connections For Three-Phase High Impedance Differential Protection - ABB Relion 670 Series Applications Manual

Section 6
Differential protection
6.1.3

Connection examples for high impedance differential protection

6.1.3.1

Connections for three-phase high impedance differential protection

Generator, reactor or busbar differential protection is a typical application for three-phase high
impedance differential protection. Typical CT connections for three-phase high impedance
differential protection scheme are shown in figure 46.
L1
(A)
CT 1200/1
Star/Wye
Connected
CT 1200/1
Star/Wye
Connected
L1
(A)
ANSI09000169 V3 EN-US
Figure 46: CT connections for high impedance differential protection
Pos
1
2
110
WARNING! USE EXTREME CAUTION! Dangerously high voltages might be present
on this equipment, especially on the plate with resistors. De-energize the primary
object protected with this equipment before connecting or disconnecting wiring or
performing any maintenance. The plate with resistors should be provided with a
protective cover, mounted in a separate box or in a locked cubicle. National law and
standards shall be followed.
L2 L3
(B) (C)
1
Protected Object
L2 L3
(B) (C)
Description
Scheme grounding point
It is important to insure that only one grounding point exist in this scheme.
Three-phase plate with setting resistors and metrosils. Protective ground is a separate 4 mm screw
terminal on the plate.
7
1
AI01
2
(I)
3
AI02
4
(I)
5
AI03
6
(I)
7
AI04
8
(I)
9
AI05
1
(I)
0
1
AI06
1
1
(I)
2
N
L3 (C)
L2 (B)
L1 (A)
N
L3 (C)
L2 (B)
L1 (A)
X1 11 12 13 14
2
3
3-Ph Plate with Metrosils and Resistors
GUID-8C58A73D-7C2E-4BE5-AB87-B4C93FB7D62B v5
GUID-C12CCAAF-5AE5-4A9C-AC9C-F56A66FD2C14 v8
SMAI2
BLOCK AI3P
^GRP2_A AI1
^GRP2_B AI2
^GRP2_C AI3
^GRP2_N AI4
TYPE AIN
IED
4
5
1 2 3 4 5 6 7
X X
6
ANSI09000169_3_en.vsd
Application manual
1MRK 511 358-UUS A