Connection Examples For High Impedance Differential Protection - ABB RELION 670 Series Installation Manual

1MRK 514 026-UEN B
6.1.1.4
670 series 2.2 IEC
Installation manual

Connection examples for high impedance differential protection

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.
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 24.
L1 L2 L3
(A) (B) (C)
CT 1200/1
Star/Wye
Connected
Protected Object
CT 1200/1
Star/Wye
Connected
L1 L2 L3
(A) (B) (C)
IEC07000193 V5 EN-US
Figure 24: CT connections for high impedance differential protection
Pos Description
1 Scheme earthing point
It is important to insure that only one earthing point exist in this scheme.
2 Three-phase plate with setting resistors and metrosils. Protective earth is a separate 4 mm
screw terminal on the plate.
7
1
2
3
4
5
6
7
8
9
1
0
1
1
1
1
2
N
L3 (C)
L2 (B)
L1 (A)
N
L3 (C)
L2 (B)
L1 (A)
X1 11 12 13
2
3
3-Ph Plate with Metrosils and Resistors
Section 6
Connecting
GUID-8C58A73D-7C2E-4BE5-AB87-B4C93FB7D62B v5
GUID-C12CCAAF-5AE5-4A9C-AC9C-F56A66FD2C14 v8
SMAI2
BLOCK G2AI3P
AI01
REVROT G2AI1
(I)
^GRP2L1 G2AI2
^GRP2L2 G2AI3
AI02
^GRP2L3 G2AI4
(I)
^GRP2N G2N
AI03
(I)
AI04
(I)
AI05
(I)
AI06
(I)
IED
4
5
1 2 3 4 5 6 7
14
X X
6
IEC07000193-5-en.vsdx
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