The type of cables used on your energy chains, drag chains and cable carriers, directly affect machine reliability, cycle life and maintenance expenses. They are the heart of any moving automation system that move, guide and protect cables and hoses, but their performance depends on the cables that they carry. The wrong or poorly specified cable could result in conductor breakage, jacket abrasion, signal interference or unexpected downtimes, which are unacceptable in today’s competitive marketplace for any OEM.
With over 20 years of experience manufacturing high flexibility cables, servo, and robot torsion cables, and industrial Ethernet solutions at Hulk Electric, we have helped many OEMs design robust cable management systems. This guide offers practical tips for what really counts when it comes to choosing and mounting cables in energy chains, drag chains and cable carriers to ensure machines perform as they are supposed to the first time.
Terminology 101 – Energy Chains, Drag Chains and Cable Carriers
In the industry, the terms energy chains, drag chains and cable carriers are frequently used synonymously. They are all flexible, link based or tubular systems which direct and shield the electrical cables, pneumatic hoses, and hydraulic lines during multiple linear or multi-axis movements.
These are typically rectangular in cross section, with crossbars or lids, separators and mounting brackets as internal components. Some people refer to them as “energy chains” (power transmission), “drag chains” (pulling action) or even a more generic term “cable carriers”, but the answer is always the same: they are designed to prevent tangling, over bending, abrasion and corkscrewing while ensuring smooth and high speed operation over millions of cycles.
The OEM design team needs to understand the terminology so they can communicate effectively with their suppliers and also ensure consistent documentation.
Why Cable Choice Is as Important as Carrier Choice
There are many OEMs who put a high emphasis on their carrier selection but don’t look at the cables so closely. The result of this is that the project will fail early. Even with the best designed energy chain, it is not possible to overcome cables that have not been rated for continuous flex.
These general-purpose static cables are not made from as fine a stranding, do not have optimal lay lengths, and are not designed to have a durable jacketing for millions of bending cycles. Meanwhile, cables made by companies such as Hulk are specifically designed for such applications and are available in drag chain. The use of both the carrier and compatible high-flex cables together as an integrated system is critical for long-term reliability in the robotics, CNC machine, material handling and automated assembly industries.
Key Requirements for Cables Used in Energy Chains
The first step in successful installations is cables that have been designed for the dynamic movement.
Mechanical Flexibility and Fatigue Resistance
Due to the need for high flexibility and thin strands of copper conductors, and the requirement to use special core twisting or lay designs to reduce the internal stress, drag-chain cables are difficult to build. Superior fatigue resistance in high bend radii and high acceleration is achieved here by Hulk’s high-flexible cables and robot torsion cables.
Bend Radius and Continuous Flex Rating
Ensure minimum continuous bending radius of the cable is matched to (or less than) the minimum radius of the carrier. The cable service life will be significantly reduced if the bend radius is exceeded. A continuous-flex rating should be cross-referenced with manufacturer test data representative of actual travel distances, speeds and cycles.
Environmental and EMC Requirements
Think of operating conditions such as oils and coolants, extreme temperatures, UV or electromagnetic interference. Choose cables of suitable jacket material, insulation and shielding. Hulk provides variants that are halogen free, oil resistant and protected for harsh applications like Servo & Motor cables, Industrial Ethernet cables (CAT5e to CAT7A) for PROFINET and EtherCAT networks.
Sizing Carriers Based on Cables – Height, Width and Fill Factor
With proper-sized carriers, friction, overheating and wear are avoided.
Inner Height and Clearance Around Cables
When measuring minimum inner height, increase the diameter (outer diameter, OD) of electrical cable by ~10%, and for hoses by 15-20%. Keep 1-3 mm of space between each cable and/or each hose to ensure freedom of movement without compression.
Inner Width and Fill Factor
Compute the width of the inside and add the diameter of the cable plus widths of separators and safety margins. To allow cables to flow freely and to prevent binding and excessive heat build-up during operation, industry guidelines suggest a cavity fill factor under 60% should be maintained.
Layout and Segregation – Keeping Cables and Hoses from Damaging Each Other
Some problems occur because of random loading within the carrier.
Keeping Unlike Components Apart
Ensure power cables are separated from signal or data cables and electrical lines are maintained away from pneumatic or hydraulic lines. For varying diameters or jacket materials use internal dividers. Hulk’s sensor & actuator cables and Fieldbus cables work best when segregated to ensure signal integrity.
Limiting Compartment Height and Stacking
Avoid excessive stacking. The height of the compartment should not be more than 1.5 times the highest cable diameter in the compartment. For speedier applications, it’s best to use full separation to avoid tangling.
Strain Relief and Neutral Axis
Use single strain relief at each end of the cable, both at the fixed and the moving end. The neutral axis of the chain is the most important, and the cables are to be neither too tight nor too loose.Installation Practices OEMs MUST call out in Documentation
Installation Practices OEMs Must Call Out in Documentation
Easy-to-follow directions in your machine documentation ensure that integrators and end users get the best results.
Handling and Installing Cables into Carriers
Install cables in a straight line, no twists. Always uncoil reels from the side and not the top. Test the system during commissioning at low speed to ensure smooth movement and alignment of the system before it is run at full capacity.
Anchoring and Strain Relief at Fixed and Moving Ends
Tie or clamp each cable in turn securely. Make sure that the carrier anchors are perfectly lined up to prevent lateral forces/torque. When properly installed using these best practices, Hulk’s high flex cables perform well.
Common OEM Mistakes with Cables Inside Carriers
As experience has revealed, there are recurring problems which are easily avoided:
- Using conventional cables rather than continuous-flex drag-chain rated cables.
- Undersizing carriers and not paying attention to clearance/fill rules, resulting in high friction.
- Imperfect isolation between power, signal and data lines, which can cause interference or damage to the lines.
- Poor strain relief that leads to pulled conductors or teared jacket.
These errors cause wear, reduce EMC performance and frequency of maintenance.
OEM Specification Checklist – What to Put in Your Machine Requirements
Make sure to add the following to the technical specifications:
- The types of cable to be used are approved: drag-chain rated, continuous-flex, required environmental properties, and shielding.
- Min Bend Radius matching of carrier and cables
- Carrier sizing rules (inner dimensions, clearance, maximum 60% fill)
- Layout and segregation requirements (separators, power/signal separation)
- Thoroughly detailed installation instructions, including uncoiling, strain relief, and alignment details.
- Maintenance information (inspection periods, replacement criteria by cycles)
Final Guidance – Design Cables and Carriers Together from Day One
However, energy chains, drag chains and cable carriers can only function at their maximum efficiency when combined with properly specified, continuous-flex cables and layout practices. OEMs ensure greater reliability, reduced field problems and competitive edge by considering the cable-carrier system as a key component of the machine design process.
We are experts in high-flexible cables, servo cables, robot torsion cables and custom-engineered cables that are specifically engineered to fit energy chain applications. Manufactured with strict quality systems, our UL, CE, TÜV and other certified products help you to achieve the highest demands in your automation projects. Let you and your team know what you are looking for in your application, and we help you find or build the perfect cables for maximum performance within your energy chains and drag chains.
