Why Use VFD Cables?

VFD cables are a critical component in order to extend a motor’s life cycle within a VFD system. Three areas where VFD cables set themselves apart from traditional tray-rated power cables are:

1. Address high and low frequency noise issues with proper shielding

Shielding on cables is what prevents systems from interacting with each other. In short, a cable’s shield is its defense against noise. THHN and most generic control/tray cable are constructed using either an aluminum shield or they are unshielded. HELUKABEL’s VFD cables are constructed using either a foil (100% coverage) + tinned copper braid (85% coverage), or a triple shield comprising of a semi-conductive fleece + foil + braid shield (80% coverage). Cables with the proper shielding prevent the VFD system from radiating electrical noise that can interfere with surrounding networking, instrumentation, wireless communication, and industrial devices.

2. Ability to withstand voltage spikes/reflected wave voltage

A cable combats voltage spikes with insulation material and wall thickness. HELUKABEL’s VFD cables use XLPE insulation as its conductor insulation. XLPE has a much lower capacitance (higher corona inception voltage) than THHN and generic control/tray cable which just use PVC. This is particularly important in wet or damp environments as PVC is more susceptible to absorbing moisture, which results in less than half the insulation capability of XLPE. The wall thickness of a VFD cable tends to be thicker allowing it to withstand voltage spikes significantly better.

The current NFPA guidelines require RHH, RHW, RHW-2, XHH, XHHE or XHHW-2 insulation for use inside the motor’s control panel or cabinet, but the expectation is this requirement will move to include cable used in external wiring of VFD applications in the upcoming years.

3. High temperature resistance

A cable’s type of insulation plays a significant role in how it responds to thermal stress. Thermoset insulation won’t melt or drip in higher temperatures like the thermoplastic insulation found in THHN and generic control/tray cables. If thermoplastic insulation is used, you run the risk that it will melt, drip, or simply deform, which reduces the insulation properties, and can cause damage to critical and expensive equipment/machinery.

UL-Listed VFD Cable Products

TOPFLEX® 600 VFD

  • XLPE Insulation, EMC-preferred Type, Flexible Motor Power Supply Cable, Oil-resistant, NFPA 79 Ch. 4

TOPFLEX® 650 VFD

  • XLPE Insulation, EMC-preferred Type, Flexible Motor Power Supply w/ Control Conductors, Oil-resistant, NFPA 79 Ch. 4

TOPFLEX® 1000 VFD

  • XLPE Insulation, EMC-preferred Type, Flexible Motor Power Supply w/ 3 Symmetrical Ground Conductors, Oil-resistant, NFPA 79 Ch. 4

TOPSERV® 600 VFD

  • XLPE Insulation, EMC-preferred Type, Highly Flexible Motor Power Supply Cable, Oil-resistant, NFPA 79 Ch. 4

TOPSERV® 650 VFD

  • XLPE Insulation, EMC-preferred Type, Highly Flexible Motor Power Supply w/ Control Conductors, Oil-resistant, NFPA 79 Ch. 4