Automatisation industrielle

High-Performance, High-Flex Cable for VFD Applications

Do you require VFD (Variable Frequency Drive) cable for on-machine applications, where it will be in constant motion? Or what about needing it for installation in tight spaces? Until recently, these situations have been challenging to resolve. On one hand, construction-grade VFD and standard THHN building wire or tray cable don't provide adequate VFD system protection or  pliability. On the other hand, high-performance Belden VFD cable has not had the extreme flexibility needed.

By controlling motors at variable speeds, VFDs save energy and improve process control. However, they also generate electrical noise that radiates out and can disrupt equipment, networks and control systems. Such disruptions can lead to intermittent process variability and even downtime. High performance VFD cable solves the electrical noise problem by having sufficient grounding, insulation, shielding and industrial hardening to protect network and control system infrastructure.


The good news is that high performance AND high flex Belden VFD cable is now available. Let's review the VFD applications that require very flexible cable and see how our new offerings make installation easier without sacrificing any of the crucial elements needed for high performance.


High Flex VFD Cable Applications

There are two general categories of VFD applications that require highly flexible cable:


1. Constant Motion Applications: In these VFD applications motors are mounted on machines or robots, such as in automotive manufacturing or on industrial equipment like injection molding machines. These applications require NPFA 79 (National Fire Protection Association) compliance for constant motion. (In Europe a similar standard is IEC 602041.1.)


2. Applications Where Flexible Cable Makes Installation Easier: For these VFD applications, the ability to manipulate the cable is important. Examples include VFDs that are used to:

  • Run process equipment and machinery
  • Power pumps to move fluids
  • Drive fans to move air
  • Run conveyors to transport a wide range of materials
  • Move robotic arms for a variety of purposes

These situations often require large cables be routed up into tight spaces in cabinets where improved bend radius and flexibility are key for easy installation.


Flexible Cable for VFD Applications - Requirements

To meet the needs of the applications described above, select VFD cable with:

  • Sufficient Flex – multiple ranges of flexibility are needed, with up to 10 million flex cycles for constant movement and on-machine applications, as per NFPA 79.

  • Easy Handling – finely stranded tinned copper conductors (with 2,000 individual strands or more) and pliable industrial-grade TPE jackets make the cable easy to handle during installation.

  • Hardening to contain noise and withstand harsh conditions – VFD cable in particular needs to be engineered for optimum electrical performance and physical toughness, going well beyond construction-grade specifications. Shielding, grounding, insulation and stranding are important.
    • For insulation, check that it is constructed of cross-linked polyethylene (XLPE). XLPE withstands voltages 3x higher than PVC/nylon does, protecting VFD systems. XLPE also increases the efficiency of power transfer from the motor to the drive and allows for longer cable runs.

  • High copper content - high copper controls the electrical noise generated by VFDs, improving VFD system performance and reliability. Some brands sacrifice copper protection to reduce costs - be sure that the cable you select has adequate copper for the application. The grounding and foil/braid designs of Belden's new high flex VFD cables, shown below, particularly control electrical noise.

Belden’s new line of High Flex VFD cable.

  • UL, C(UL), IEC and other ratings - a full range provides application versatility.
  • Long warranty – a 10-year guarantee of reliable installed performance reduces TCO (Total Cost of Ownership).

High Flex and High Performance VFD Cable Delivers the Best Return

Selecting and specifying VFD cable is difficult because there are no standards for them. There are many cables on the market today which claim to be VFD cables, many of which do not work well and lead to costly VFD system issues, downtime and even safety issues.


Belden's new high flex VFD cable is highly engineered to both protect VFD systems from electrical noise and deliver high flexibility for easy installation. Remember, the amount of copper in the cable and proper installation are the two critical components which most directly impact VFD system performance.


Now it’s possible to transmit the power needed to run industrial machine motors for constant motion or tight space applications with very high reliability.