Siemens Simatic S7-300 - Bonding the Protective Conductor to the Profile Rail

Wiring
S7-300 Programmable Controller Hardware and Installation
6-4 A5E00105492-01
6.2 Bonding the protective conductor to the profile rail
Prerequisite
The profile rail is fixed to the mounting surface.
Connecting the protective conductor
1. Connect the protective conductor to the rail,
using the M6 protective conductor bolt.
Minimum cross-section of the protective conductor: 10 mm
2
.
The figure below shows how the protective conductor must be bonded to the profile
rail.
Figure 6-1 Bonding the protective conductor to the profile rail
Note
Always ensure a low-impedance connection of the protective conductor. You can
achieve this by bonding a cable with low impedance and as short as possible to a
large contact surface.
For example, if the S7-300 is mounted on a hinged frame you must use a flexible
ground strap.