Grounding Concept; Emc Compatibility - Siemens SINUMERIK 840D sl Equipment Manual

7.2.2

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 Pushbutton 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 (e.g. tension jacks) must be removed.
It is permissible to cluster the operator control components regarding connection/potential
bonding.
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.
Please note that interruption of the grounding during maintenance work is not permissible.
Note
Proper grounding of the device and the machine corresponding to the EMC Design Guidelines
is absolutely necessary for the function of the touch screen.
Additional references
EMC Design Guidelines
7.2.3

EMC compatibility

In addition to the protective grounding of system components, special precautions must be
taken to guarantee safe, trouble-free operation of the system. These measures include shielded
signal lines, special equipotential bonding connections, and isolation and shielding measures.
Operator panel front: OP 010S
Equipment Manual, 12/2022, A5E50751046B AA
Technical specifications
7.2 Secondary electrical conditions
35