Many existing variable frequency drive (VFD) installations are using wrong cables. Often, interlocked armor TECK or continuously welded and corrugated aluminum armor (CCA) cable are used to connect the VFD to the motor. These cable types will release excessive electrical noise in many installations - and this electrical noise can wreak havoc with the sensitive electronic components, network cabling and other sensitive wiring found in most modern industrial facilities.
The solution is to use specially-designed VFD cable with a foil braid or copper tape shield and suitable ground wires. For larger cables it becomes important to use a symmetric ground design to balance the induced ground currents. Compared to TECK or CCA, this type of VFD cable provides superior performance in terms of common mode current (CMC) containment, and in other areas.
Recently, Belden announced an extension to its VFD cable line to include 250 MCM, 350 MCM and 500 MCM sizes. These MCM VFD cables (see datasheet) support installations of up to 250 horsepower motors at 460V for use in oil & gas, petrochemical, power generation, water/wastewater treatment and other demanding industrial environments.
Belden MCM VFD cables are rated for use in exposed-run cable trays, direct burial and in wet or dry conditions. Belden’s MCM VFD cables are designed to provide superior performance in noise-sensitive applications or in any damp or wet environment where reflected wave voltages may degrade PVC/nylon conductors. The cable is suitable for use with virtually all variable frequency drives, as well as for use as shielded power cable for other solid-state devices.
You can read more about how to select and install the right cable for your VFD motors. A recently produced white paper is now available.