ABB Relion 670 Series Applications Manual page 125

1MRK 511 401-UEN Rev. K
7.1.3 Connection examples for high impedance differential
protection
7.1.3.1 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 51.
CT 1200/1
Star/Wye
Connected
CT 1200/1
Star/Wye
Connected
IEC07000193 V5 EN-US
Figure 51:
Pos
1
2
3
4
5
Bay control REC670
Application manual
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.
L1 L2 L3
(A) (B) (C)
1
Protected Object
L1 L2 L3
(A) (B) (C)
CT connections for high impedance differential protection
Description
Scheme earthing point
It is important to insure that only one earthing point exist in this scheme.
Three-phase plate with setting resistors and metrosils. Protective earth is a separate 4 mm screw
terminal on the plate.
Necessary connection for three-phase metrosil set.
Position of optional test switch for secondary injection into the high impedance differential IED.
Necessary connection for setting resistors.
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7
1
AI01
2
(I)
3
AI02
4
(I)
5
AI03
6
(I)
7
AI04
8
(I)
9
AI05
1
(I)
0
1
1 AI06
1
(I)
2
N
L3 (C)
L2 (B)
L1 (A)
N
L3 (C)
L2 (B)
L1 (A)
11 12 13 14 1
X1
2
3
3-Ph Plate with Metrosils and Resistors
Differential protection
GUID-8C58A73D-7C2E-4BE5-AB87-B4C93FB7D62B v5
GUID-C12CCAAF-5AE5-4A9C-AC9C-F56A66FD2C14 v8
SMAI2
BLOCK G2AI3P
REVROT G2AI1
^GRP2L1 G2AI2
^GRP2L2 G2AI3
^GRP2L3 G2AI4
^GRP2N G2N
IED
4
5
2 3 4 5 6 7
X X
6
IEC07000193-5-en.vsdx
Section 7
119