ABB Relion 670 series - Connecting to Protective Earth

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.
6.1.2 Connecting to protective earth
M11997-4 v10
Connect the protective earthing screw (pos 1 in figure 26) on the rear of the IED to
the closest possible earthing point in the cubicle. Electrical codes and standards
require that protective earth cables are green/yellow conductors with a cross
section area of at least 2.5 mm
2
(AWG14).
The cubicle must be properly connected to the station earthing system. Use a
conductor with a core cross section area of at least 4 mm
2
(AWG 12).
IEC05000509=2=en=Original.vsd
1
IEC05000509 V2 EN-US
Figure 26: Rear view of IED showing the earthing point
Pos
Description
1 Protective conductor terminal. For connection of the external
protective (earth) conductor.
Use the protective conductor terminal (1) for connection to the
stations earthing system.
1MRK 514 026-UEN B Section 6
Connecting
670 series 2.2 IEC 51
Installation manual