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Showing posts from July, 2025

Preventing induced EMF from VFD cables in cable trays

  Preventing induced EMF (electromagnetic interference) from VFD cables in cable trays requires physical separation, proper shielding, and correct grounding practices . VFDs generate high-frequency EMI from fast switching speeds that induces noise into adjacent control and instrumentation cables. Key Prevention Strategies Strategy Implementation Effectiveness Physical Separation Maintain minimum 8-inch (20cm) separation between VFD power cables and control/instrumentation cables  Critical Segregation with Metal Barriers Use solid metal divider strips inside same tray (height = side-rail height) OR install dedicated separate trays for VFD power vs control cables  High Use Shielded VFD Cable Specify copper tape-shielded VFD cable with XLPE insulation (not unshielded or braided)  Essential Ground Shield at Both Ends Terminate VFD cable shield at drive end AND motor end to provide low-impedance path for noise current  Critical Bond Cable Trays Ensure all cable...