Why Use VFD Cables? HELUKABEL Answers

Janaury 26, 2023

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

Why Use VFD Cables? VFD cables are a critical component 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 cables 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/CSA VFD Cable Products

TOPFLEX®

 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®

 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

Complete Your Cable System

EMC glands improve VFD cable perfromance and protect your equipment from the harmful effects of electromagnetic interference

Further enhance your electric motor’s lifespan by using EMC glands to protect your equipment from electromagnetic interference. EMC glands perform a key function in EMC protection by deflecting electromagnetic waves over the housing surface at a critical transition point – entry into the enclosure – in order to protect the exposed cables inside.

Thanks to their enlarged contact surfaces, EMC cable glands improve conductivity between the cable shield and gland on the enclosure housing. With their copper beryllium contact system, products such as the HELUTOP®  MS-EP and  MS-EP4 ensure excellent shielding attenuation and current dissipation. Contact is made automatically when the gland is tightened, and the polyamide PA 6 insert provides perfect strain relief.

Put to the Ultimate Test Cables and wires in industrial robots and other moving machine parts are often required to withstand extreme stresses caused by torsion. Find out how HELUKABEL puts their cables to the ultimate test. Read Part 1: Torsion Tests by HELUKABEL

Related Articles


Changing Scene

  • RS Partners With Hammond Manufacturing to Provide Custom Electrical and Electronic Enclosures

    RS Partners With Hammond Manufacturing to Provide Custom Electrical and Electronic Enclosures

    RS Group plc offers more than 4,900 fully customizable electrical and electronic enclosures from Hammond Manufacturing, in addition to more than 2,900 supporting products. Enclosures are used to connect and protect two or more electrical and electronic components and devices. They are employed in virtually every commercial and industrial application, and every enclosure gets modified in some way. Read More…

  • Schneider Electric Appoints Hugo Lafontaine to Lead Its Industry Business in Canada

    Schneider Electric Appoints Hugo Lafontaine to Lead Its Industry Business in Canada

    Schneider Electric, the leader in the digital transformation of energy management and automation, announces the appointment of Hugo Lafontaine to the position of Vice President, Industry, Canada. Hugo will lead the company’s automation business in Canada, bringing smart, connected and sustainable digital technology and next-generation solutions to guide the advancement of industries of the future. Read More…


Sponsored Content
The Easy Way to the Industrial IoT

The way to the Industrial IoT does not have to be complicated. Whether access to valuable data is required or new, data-driven services are to be generated, Weidmuller enables its customers to go from data to value the easy way. Weidmuller’s comprehensive and cutting-edge IIoT portfolio applies to greenfield and brownfield applications. Weidmuller offers components and solutions from data acquisition, data pre-processing, data communication and data analysis.

Visit Weidmuller’s Industrial IoT Portfolio.


For a Multiplied Value Unified

PB-62-Excelpro-MultipliedValue-400.jpg

During the last few years, the Excelpro Group has welcomed AIA Automation, Envitech Automation and Conrad Lavoie Electrical, all of which have become ‘Member of the Excelpro Group’.

It was with great excitement that in November of 2022, Excelpro announced that these three companies officially became Excelpro. This decision is part of a strategy to enhance the Excelpro Group’s brand in its market.

These companies already collaborate on various client projects. This merger brings together the complementary strengths of the employees and ensures a global synergy of the activities throughout the Group.

Read More


Service Wire Co. Announces New Titles for Key Executives

Bruce Kesler and Mark Gatewood have been given new titles and responsibilities for Service Wire Co.

Bruce Kesler has assumed the role of Senior Director – Business Development. Bruce will be responsible for Service Wire’s largest strategic accounts and our growing Strategic Accounts Team.

Mark Gatewood has been promoted to the role of Vice President – Sales & Marketing. In this role, Gatewood will lead the efforts of Service Wire Company’s entire sales and marketing organization in all market verticals.

Read More


Tri-Mach Announces the Purchase of an Additional 45,000 sq ft. Facility

Tri-Mach Elmira Facility

Recently, Tri-Mach Inc. was thrilled to announce the addition of a new 45,000 sq ft. facility. Located at 285 Union St., Elmira, ON, this facility expands Tri-Mach’s capabilities, allowing them to better serve the growing needs of their customers.

Positioning for growth, this additional facility will allow Tri-Mach to continue taking on large-scale projects, enhance product performance testing, and provide equipment storage for their customers. The building will also be the new home to their Skilled Trades Centre of Excellence.

Read More


JMP Parent Company, CONVERGIX Acquires AGR Automation, Expanding Global Reach

Convergix Automation Solutions has completed the acquisition of AGR Automation (“AGR”), a UK-based provider of custom, high-performance automation design and systems integration primarily to the life sciences industry.

Following Convergix’s acquisitions of JMP Solutions in August 2021 and Classic Design in February 2022, AGR marks the third investment in Crestview’s strategy to build Convergix into a diversified automation solutions provider targeting the global $500+ billion market, with a particular focus on the $70 billion global systems integration and connectivity segments. Financial terms of the transaction were not disclosed.

Read More


Latest Articles

  • What’s the Best Way to Guard AS/RS with Safety Light Curtains?

    What’s the Best Way to Guard AS/RS with Safety Light Curtains?

    Automated storage and retrieval systems (AS/RS) are a popular way to make storage space usage more efficient and cut down on manual labor. Although these systems also improve safety by eliminating the need for people to manually access shelving, safeguarding is still required to keep people out of hazardous areas. Safety light curtains are a key element in any AS/RS safety solution. The main challenge in AS/RS safeguarding is that the safety system needs to allow totes to enter the danger zone while keeping people out. Read More…

  • Rittal, Eplan, Cideon and GEC at Hannover Messe 2023

    Rittal, Eplan, Cideon and GEC at Hannover Messe 2023

    Industry is under tremendous pressure to change. How is the manufacturing industry progressing toward smart production? How can we move from crisis management to long-term transformation in energy, efficiency and sustainability? How can we speed up the much-needed scaling up of infrastructure? How are companies countering the shortage of skilled workers? Rittal, Eplan, Cideon and German Edge Cloud will discuss these questions with visitors to the Hannover Messe, showing how expertise can be used to create comprehensive solutions in the relevant ecosystems. Read More…