Ri Suppression Measures - Siemens SINUMERIK 840D sl Equipment Manual

4.1.1.3

RI suppression measures

In addition to the protective grounding of system components, special precautions must be
taken to ensure safe, fault-free operation of the system. These measures include shielded signal
lines, special equipotential bonding connections, and isolation and shielding measures.
Shielded signal cables
• Use the specified cables for safe and fault-free operation of the system.
• Connect the shield conductively at both ends to the housing for digital signal transmission.
Cable definition
Definition:
• Signal cables (example)
– Data cables (Ethernet, PROFIBUS, sensor cables, etc.)
– Digital I/Os
– Cables for safety functions (emergency stop, enabling)
• Power cables (example)
– Low-voltage supply lines (230 VAC, +24 VDC, etc.)
– Motor cables
Rules for routing cables
In order to achieve the greatest possible EMC compatibility for the complete system (control,
power unit, machine), the following EMC measures must be carefully observed:
• If necessary, signal and power cables may cross one another (if possible at an angle of 90°),
but must never be laid close or parallel to one another.
• Only use cables approved by SIEMENS for the signal lines from and to the Control Unit.
• Signal cables must not be routed close to strong external magnetic fields (e.g. motors and
transformers).
• If signal lines cannot be routed a sufficient distance away from other cables, they must be
installed in grounded cable ducts (metal).
• The operator panel fronts, MCPs, MPPs, and full keyboards must be installed in metallically
enclosed EMC-compatible housings.
Further information on RFI suppression measures and the connection of shielded cables can
be found in the EMC Installation Guidelines.
Handheld Terminal HT 8
Equipment Manual, 02/2024, A5E52918633B AA
General information and networking
4.1 Application planning
25