____________________________________________________________________________________________________________
V2
AC500 Hardware
1-38 System
data
AC500 / Issued: 05.2007
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.
CS31
Sh
ie
ld
BU
S
2
BU
S
1
slave
C
S
3
1
syst
e
m
b
u
s
CS31
slave
C
S
3
1
syst
e
m
b
u
s
1
2
3
4
120
Ohms
COM1
PE
CS31 bus master
e.g. PM581
Cabinet 1
Cabinet 2
current-carrying connection
current-carrying connection
direct earthing of shields
when entering the cabinet
Figure: Direct earthing