![background image](http://html1.mh-extra.com/html/abb/relion-670-series/relion-670-series_applications-manual_3052129106.webp)
5
Necessary connection for setting resistors.
6
Factory-made star point on a three-phase setting resistor set.
The star point connector must be removed for installations with 670 series IEDs.
This star point is required for RADHA schemes only.
7
Connections of three individual phase currents for high impedance scheme to three CT inputs in the
IED.
6.1.3.2
Connections for 1Ph High impedance differential protection HZPDIF
GUID-D68A237F-610C-4AF0-870F-273117F64D92 v10
Restricted earth fault protection is a typical application for 1Ph High impedance differential
protection HZPDIF. Typical CT connections for the high impedance based protection scheme
.
L1
(A)
L2
(B)
L3
(C)
Protected Object
CT 1500/5
Star/Wye
Connected
7
8
9
10
11
12
1
2
3
4
5
6
AI01 (I)
AI02 (I)
AI03 (I)
AI04 (I)
AI05 (I)
AI06 (I)
6
X1
R
1
1
2
4
5
U
R
2
1
3
4
2
1
2
3
N
1-Ph Plate with Metrosil and Resistor
2
3
5
4
N
L1
(A)
L2
(B)
L3
(C)
CT
1
50
0/
5
1
IEC07000194_4_en.vsd
AI3P
AI1
AI2
AI3
AI4
AIN
SMAI2
BLOCK
^GRP2L1
^GRP2L2
^GRP2L3
^GRP2N
TYPE
IEC07000194 V4 EN-US
Figure 35: CT connections for restricted earth fault protection
Pos
Description
1
Scheme earthing point
Ensure that only one earthing point exists in this scheme.
2
One-phase plate with stabilizing resistor and metrosil. Protective earth is a separate 4 mm screw
terminal on the plate.
3
Necessary connection for the metrosil.
4
Position of optional test switch for secondary injection into the high impedance differential IED.
5
Necessary connection for stabilizing resistor.
6
How to connect the high impedance restricted earth fault protection scheme to one CT input in IED.
Section 6
1MRK 505 343-UEN B
Differential protection
100
Application manual
Summary of Contents for Relion 670 series
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