EMI Noise Reduction

Electromagnetic Fields!

Electromagnetic radiation may lead to potential hazardous danger (warming, failure of implants), when acting on electrically conductive materials.

  • Work on the electrical installation may only be performed by trained and qualified personnel, in compliance with the regulations for safety at work, and only with switched off mains supply and secured against restart.
  • Do not remove grounding, equipotential bonding and radiation-reducing shields.

Reducing EMI noise

With the help of the following instructions, you can reduce electrical interference in the application:

  • Ensure good connections between the cabinet components. Connect the back panel and cabinet door to the cabinet body using several conductive braids. Never rely on hinges or mounting bolts for ground connections.
  • Ensure good ground connection. Connect from cabinet to proper earth ground. Ground leads should be the same gauge as the leads to main power, but must cover the regional legal requirements, example (see "Protective Earth Connection").
  • Use Kollmorgen cables. Route power and control cables separately, Kollmorgen recommends a distance of at least 200 mm to improve interference immunity.
  • Ground the shielding at both ends. Ground all shielding with large areas (low impedance), with metalized connector housings or shield connection clamps wherever possible. For cables entering a cabinet, connect shields on all 360° of the cable. Never connect a simple “pigtail.” For more information on shielding concepts, (see "Shielding with external shielding busbar").
  • With separate mains filter, maintain separation of leads entering and exiting the mains filter (line power filter). Locate the filter as close as possible to the point where the incoming power enters the cabinet. If it is necessary for input power and motor leads to cross, cross them at 90°.
  • Observe cable length limits. Maximum distance for unshielded I/O lines is 3 m inside the cabinet. If the I/O cable leaves the cabinet, it must be EMC shielded.
  • Feedback lines and Hybrid Cables may not be extended, since the shielding would be interrupted and the signal processing may be disturbed.Install all feedback cables with an adequate cross-section, per IEC 60204 (see "Cable and Wire Requirements") and use the requested cable material to reach maximum cable length.
  • Splice cables properly. If you need to divide cables, use connectors with metal backshells. Ensure that both shells connect along the full 360° of the shields.
  • Use differential inputs for analog signals. Noise susceptibility in analog signals is greatly reduced by using differential inputs. Use twisted-pair, shielded signal lines, connecting shields on both ends.
  • Cables between drives and filters or external regen resistors must be shielded. Install all power cables with an adequate cross-section per IEC 60204 (see "Cable and Wire Requirements") and use the requested cable material to reach maximum cable length.