Grounding - Siemens SIMATIC NET PROFIBUS Owner's Manual

Passive Components for RS-485 Networks
4.7.5

Grounding

If the bus terminal is mounted on a DIN rail (see Figure 4-33), the shield clamp
makes large-area contact with the rail via an internal spring. To connect the cable
shield with local ground, a connection between the DIN rail over as short a
distance as possible to local earth is adequate.
Installation on closet panel
with securing screws
MADE IN GERMANY
Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó
Bus
terminated
PE
PE
A B A B
2
)
Ñ Ñ
1)
Shield clamp/
grounding bar
1) If this grounding cable exceeds a length of 20 cm,
the shield must be grounded to the closet panel (2).
Figure 4-33 Ways of Installing and Grounding the Bus Terminal
Note
The grounding bar and local ground must be connected by a Cu conductor with
2
6 mm cross-section over as short a distance as possible.
4-58
Wall installation with securing
screws
MADE IN GERMANY
Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó
Bus
terminated
PE PE
A B A B
Ñ Ñ Ñ Ñ Ñ Ñ
Shield clamp/
grounding bar
Installation with a standard rail
on a cabinet panel
MADE IN GERMANY
MADE IN GERMANY
Ó Ó Ó Ó Ó Ó Ó Ó Ó
Ó Ó Ó Ó Ó Ó Ó Ó Ó
Bus Bus
terminated terminated
PE PE P
E
A B A B A B
Ñ Ñ Ñ Ñ Ñ Ñ
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
P
E
A B