Connecting 
  6.3 Protective ground connection 
SIMATIC IPC427C 
Operating Instructions, 04/2009, A5E02414743-01 
35 
6.3  Protective ground connection 
 
The PE terminal (M4 thread) on the device (large surface, large-area contact) must be 
connected to the PE conductor on the cabinet or system in which the PC is to be installed. 
The conductor cross-section must not be less than 2.5 mm
2
. 
The PE terminal is needed to protect the device and ensures that interference signals 
generated by external power cables, signal cables or cables to the I/O modules are safely 
discharged to earth. 
Required tool for protective earth terminal: TORX T20 screwdriver 
 
Protective earth terminal  
Connect the PE terminal (M4 thread) 
① on the device to the PE conductor 
on the cabinet or system in which the 
PC will be installed. The minimum 
conductor cross-section may not be 
less than 2,5 mm
2
.