ABB AC500 PLC Hardware Manual page 1216

System Assembly, Construction and Connection
AC500-eCo > Connection and Wiring
Fig. 206: Correct
Fig. 207: Wrong
Earthing In order to avoid disturbance, the cable shields must be earthed directly.
Case A Multiple switch-gear cabinets: If it can be guaranteed that no potential differences can occur
between the switch-gear cabinets by means of current-carrying metal connections (earthing
bars, steel constructions etc.), the direct earthing is chosen.
Fig. 208: Direct earthing
1 Direct earthing with clip or steel plate
2 Earth of Cabinet 1
3 Current-carrying connection
4 Earth of Cabinet 2
1216
COM1
270 Ω
5
9
120 Ω
6
1
270 Ω
CS31
Master
2
3ADR010121, 13, en_US
1
CS31
Slave
3
4
CS31
Slave
3
2019/04/17