ABB REB 551-C3*2.5, Installation And Commissioning Manual

Page: 47 / 148

38
Installing the serial communication cable for
RS485 SPA/IEC Chapter 5
Installing the terminal
Figure 9: Communication cable installation
en03000111.vsd
Cc
External
Equipment (PC)
Terminal
A
PE
B
PE
A B
PE 1)
A B
PE
Terminal
Cc
1)
Where:
1 The inner shields shall be connected together (with an isolated terminal block) and only have one
earthing point in the whole system, preferably at the external equipment (PC).
The outer shield shall be connected to Protective Earth (PE) in every cable end i.e. to PE at all
relay terminals and to PE at External equipment (PC). The first
terminal will have only one cable
end but all others of course two.
Cc Communication cable
PE Protective earth screw