ABB RELION 670 Series Installation Manual page 75

1MRK514024-UEN A
outer shieldings are connected to the external equipment according to the installation
instructions for the actual equipment. Use insulating tape for the inner shield to prevent
contact with the IED chassis. Make sure that the IEDs are properly earthed with as short
connections as possible from the earth screw, for example to an earthed frame.
The IED and the external equipment should preferably be connected to the same battery.
1 2
X1
IEC07000141 V2 EN-US
Figure 48: Communication cable installation, 2-wire
Where:
1
2
3
4
Cc
Installation manual
Cc
3 4 5 6
IED
4)
The inner shields shall be connected together (with an isolated terminal block) and only have one
connection point in the whole system, preferably at the external equipment (PC).
The outer shield shall be connected to the IED chassis in every cable end. Use the shield connection
clamp at all IEDs. The first IED will have only one cable end but all others require two.
Connect according to installation instructions for the actual equipment, observe the 120 ohms
termination.
Connect the screens according to the installation instructions for the actual equipment.
Shield connection clamp, see Figure 30.
Communication cable
Cc
1)
1 2 3 4 5 6
X1
IED
4)
2)
External
Equipment (PC)
3)
IEC13000229-1-en.vsd
PE 1) 3)
Section 6
Connecting
69