ABB Relion 670 Series Installation Manual page 52

Section 6
Connecting
4
5
6
7
Connections for 1Ph High impedance differential protection HZPDIF (87)
Restricted earth fault protection is a typical application for 1Ph High impedance differential
protection HZPDIF (87). Typical CT connections for the high impedance based protection scheme
are shown in figure 25.
CT 1500/5
Star/Wye
Connected
ANSI09000170 V5 EN-US
Figure 25: CT connections for restricted earth fault protection
Pos
1
2
3
46
Position of optional test switch for secondary injection into the high impedance differential IED.
Necessary connection for setting resistors.
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.
Connections of three individual phase currents for high impedance scheme to three CT inputs in the IED.
L1 L2 L3
(A) (B) (C)
Protected Object
L1 L2 L3
(A) (B) (C)
1
Description
Scheme grounding point
Ensure that only one grounding point exists in this scheme.
One-phase plate with stabilizing resistor and metrosil. Protective ground is a separate 4 mm screw
terminal on the plate.
Necessary connection for the metrosil.
1
AI01 (I)
2
3
AI02 (I)
4
5
AI03 (I)
6
6
7
AI04 (I)
8
9
AI05 (I)
10
11
AI06 (I)
12
N
4
N
1
X1 4 5
2
3
1-Ph Plate with Metrosil and Resistor
1MRK 514 026-UUS F
GUID-D68A237F-610C-4AF0-870F-273117F64D92 v10
SMAI2
BLOCK G2AI3P
REVROT G2AI1
^GRP2_A G2AI2
^GRP2_B G2AI3
^GRP2_C G2AI4
^GRP2_N G2N
IED
2 3
5
ANSI09000170-5-en.vsdx
Installation manual
670 series