Maximizing Efficiency with the Right VFD Cables

Written by: Khoi Nguyen, Sr. Director of Marketing & Bus. Dev. at LAPP Tannehill

Discover tips on maximizing efficiency with VFD cables. Learn how to optimize performance and save energy in your industrial applications.

Why VFD cables?

The widespread industrial expansion across various sectors is fueling the extensive use of machinery and equipment, which increasingly depend on variable frequency drives (VFDs) to operate efficiently and effectively.

Diverse industries such as manufacturing, food and beverage, energy storage systems, renewable energy (wind, solar, grid management), automotive, material handling, wastewater treatment, pulp and paper, chemical, oil and gas, and any application requiring commercial HVAC (heating, ventilation, and air conditioning) are major users of VFD cables.

AC motor drives have traditionally been the foundation for industrial automation mainly for their reliability and low maintenance needs. Unfortunately, one of their main drawbacks is inefficient energy consumption due to always running at full speed regardless of workload.

VFDs, when paired with pumps, fans, and motors in mechanical systems, tackle this challenge by regulating the frequency and voltage supplied to the motor, enabling precise control of speed and torque to seamlessly match load requirements. As a result, VFD cables help reduce energy use, optimize costs, and help organizations meet energy-efficiency regulations.

Why is VFD-specific cable required?

VFD systems operate in unique and challenging environments which require careful consideration for cabling and electrical connections. Defaulting to standard cabling not specifically designed for VFD applications can result in issues such as Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI), reduced system efficiency, overheating, premature cable failure, and potential damage to connected equipment.

VFD systems can create a significant amount of electrical noise in the form of large voltage spikes, EMI/RFI, common-mode voltages and other electromagnetic phenomena. Voltage spikes are a particularly important consideration as VFD system cabling can be subjected to two to three times the source voltage under normal operating conditions due to the VFD drive’s switching technology.

These resultant high-voltage spikes can easily surpass a cable’s voltage rating, gradually diminishing its reliability over time with repeated high-voltage cycles. These voltage spikes increase with cable length, making longer cable runs more prone to premature cable failure. Additionally, high-voltage spikes can generate conductive and radiated noise, which can interfere with communications and low-voltage cables near the VFD cable run.

Selecting the right VFD Cable

Several key criteria must be considered when selecting VFD cable such as:

The following table provides a comparison and overview of a “good, better, best” selection of VFD cable to address most drive and motor applications covering cable for fractional/low HP motors (14 AWG cable) up to the large HP applications (1AWG to 500kcmil cable).

	HIGH-PERFORMANCE VFD CABLES
	ÖLFLEX® VFD Slim	ÖLFLEX® VFD 1XL	ÖLFLEX® VFD 2XL
Duty & Performance Rating	Light duty, Good Performance	Medium duty, Better Performance; Reduced diameter for ease of installation; Continuous flex (w/o Signal Pair)	Heavy duty, Excellent Performance
Cable Installation Distance	<50 ft (<15 meters)	50 to 300 ft (15 to 91 meters)	Up to 300ft and above (91 meters +)
Nominal Voltage	Suitable for 1000V applications	Suitable for 1000V applications	Suitable for 2000V applications
Electrical Characteristics	Good capacitance and impedance to withstand electrical irregularities	Improved dielectric characteristics	Excellent electrical properties with a Low capacitance design
Insulation & Jacket	Semiconductive “Surge Guard” insulation and PVC/NYLON jacket	Thin-walled XLPE (plus) insulation and TPE jacket	RHW-2 XLPE (plus) insulation and TPE jacket
Cable Configurations		Optional available control signal pair	Standard & symmetrical grounds designs; optional available control signal pair
Shielding	Shielding triple layer foil tape + tinned copper braid	Shielding triple layer foil tape + tinned copper braid	Shielding triple layer foil tape + tinned copper braid

ÖLFLEX® VFD Slim

As industrial spaces become more compact, the need for efficient yet space-saving solutions has never been greater. The ÖLFLEX® VFD Slim cable addresses this need with its reduced diameter and flexibility. Designed for installations where space is at a premium, the VFD Slim cable ensures you don’t compromise on performance while saving valuable real estate. Key Features:

ÖLFLEX® VFD Cables | VFD Slim, VFD 1XL, VFD 2XL

Space Efficiency: With a smaller diameter, it’s perfect for tight spaces without sacrificing functionality.
Flexibility: The cable’s flexibility makes it easier to install in complex layouts.
EMC Performance: Enhanced shielding ensures excellent electromagnetic compatibility, reducing the risk of interference with other electronic equipment.

ÖLFLEX® VFD 1XL

When you think of reliability and durability, the ÖLFLEX® VFD 1XL stands out. Designed to endure the harshest industrial environments, this cable promises long-term performance and reduced downtime. Key Features:

Robust Construction: Built to withstand mechanical stress, the VFD 1XL is perfect for environments with constant movement and vibration.
Temperature Resistance: With a wide operating temperature range, it functions reliably in both hot and cold conditions.
Oil Resistance: Superior oil resistance ensures longevity even in environments with exposure to lubricants and chemicals.

ÖLFLEX® VFD 2XL

For those who need the best of the best, the ÖLFLEX® VFD 2XL is a top-tier choice. This cable is designed for maximum performance, with features that cater to the most demanding applications. Key Features:

Extended Longevity: Enhanced materials and construction techniques provide exceptional durability, making it a long-lasting solution.
High Flexibility: Despite its robust build, the VFD 2XL maintains excellent flexibility, easing installation and maintenance.
Superior EMC Performance: With advanced shielding, it offers top-notch electromagnetic compatibility, crucial for maintaining signal integrity in complex systems.

Engineering the reliable VFD Cable “System”

A reliable VFD system is comprised of three major components (a VFD controller, the VFD cable, and VFD motor) and a robust physical and electrical connection between the three components. 

To accomplish the connectivity requirements the VFD cable connection to the other components must provide a strong 360° (physical and electrical) contact and low transfer impedance from the shield at both the motor and the drive (or drive cabinet) for reliable electrical bonding. 

A good example of shield terminating cable gland is the SKINTOP® Brush series of cord grips. SKINTOP® Brush is a nickel-plated brass strain relief for EMC applications (such as VFD systems) with an NPT or metric thread.

Technical Illustrations of SKINTOP® Brush cord grips/cable glands suitable for use with VFD cables

This provides a centered, fixed strain relief with a liquid-tight and dust-proof seal, all in one step. Simply insert the cable, push the braid shield under the innovative EMC brush, tighten the cap, and the connection is made.

LAPP Tannehill VFD Cable: In-Stock & Ready-to-Ship Today

LAPP Tannehill is a leading national distributor for VFD cable specializing in fast shipment, high service level and flexibility to meet the exact needs of every manufacturing company. 

• Fast Delivery: Same-day pickup or shipment from our warehouse locations in Houston, Las Vegas, Minneapolis/St.Paul, and Indianapolis
• Highly customizable services including cutting and tailored cable put-ups

Contact LAPP Tannehill today for all of VFD cabling requirements. Browse our product selection below, request a quote or stock-check, contact us for additional assistance or call us at 800.633.6339.