Application Planning; Secondary Electrical Conditions; Grounding Concept - Siemens NCU 7 0.2 Series Manual

Application Planning

4.1

Secondary electrical conditions

4.1.1

Grounding concept

Components
The SINUMERIK 840D sl system consists of a number of individual components which have
been designed so that the system complies with the appropriate EMC and safety standards.
The individual system components are:
● Numerical Control Unit (NCU):
● Machine Control Panel MCP, Machine Push Button Panel MPP
● Keyboard
● Operator panels (operator panel front + TCU/PCU)
● Distributor box and handheld unit
● S7-300 I/O with IM 153 interface module
Grounding measures
The individual modules are attached to a metal cabinet panel. Insulating paints on the
mounting points must be removed.
It is permissible to have a cluster of operator components for ground connection/PA.
Example: The control panel on the swivel arm.
It is sufficient in this instance to connect the ground connections of, for example, the PCU,
TCU, and operator panel front using a cable and to route a shared grounding conductor to
the central ground connection in the control cabinet.
Additional references
Configuration Manual, EMC Guidelines
NCU 7x0.2
Manual, 02/2011, 6FC5397-0AP20-0BA0
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