High-flex cables are made to withstand large amounts of stress, bending, and movement. In contrast with traditional cables, high-flex ones are, as their name suggests, able to tolerate large degrees of flexing in applications related to industrial automation such as robotics, packaging, and conveyor systems.

The best cables, including high-flex ones, wear out eventually and must be replaced. When high-flex cables are used in the wrong application or not installed correctly, they will wear out faster than if used as intended. Unplanned interruptions due to cable-related problems and the need to replace cables frequently are more expensive than doing things right the first time.

Based on our extensive experience, here are the top 5 reasons for premature failure of High-Flex Cable and how to prevent them:

#1: The quiet zone is too short. The quiet zone is the cable length supported in the cable track, such as a C-track or drag chain. It’s used to prevent cable from experiencing turns and bends that can be damaging. A quiet zone that’s too short leads to corkscrewing due to cables compensating for overload. In multi-conductor cables such as high-flex ones, conductor shifting or migration causes the cable to twist which leads to other elements being displaced, becoming worse the more the cable flexes.

What’s the solution?

Make a quiet zone that’s of ideal length for your cable. Zone length depends on variables such as the number of conductors, AWG size, shielding, and cable length. Generally, heavier cables that contain more conductors require longer quiet zones than lighter ones with fewer conductors.

#2: Improper handling. “Flex” and “Flexible” cable are two terms that mean different things to different people and have no standard definitions. As a result, many people believe that such cables can withstand rigorous conditions even though they can be damaged by excessive dragging, twisting, or carelessness during installation.

What’s the solution?

Handle high-flex cables carefully during installation. Follow the manufacturer’s installation recommendations that your shipment will contain, and unreel the cables, giving them time to “relax” for a minimum of 24 hours to regain their original characteristics before installation or termination. During installation, do not pull or drag cables along the floor or around equipment, because this can result in twisting.

To determine whether your cable is twisted, look at the print legend on the cable’s jacket. If it’s facing up in a track, in the 12:00 position, it is positioned correctly. In contrast, if the print is turning or rotating, the cable is twisting. If the cable is twisted when it’s on the track, correct the issue before proceeding with the rest of the installation.

#3: Putting too many cables in a track. Cable tracks are designed to prevent cables from becoming damaged. A crowded track, however, can break, leading to heat buildup and component failure. “Overcrowded” tracks can also hinder cables from moving freely, which results in unwanted bending or twisting.

What’s the solution?

Decrease the number of high-flex cables you put in a track. This allows cables to flex without experiencing unwanted friction or stress. Cables should lay flat in the track and never on top of each other to prevent twisting and corkscrewing. Track manufacturers provide instructions on correctly “populating” a track to avoid overcrowding and the resulting damage that could occur.

#4: Excessive abrasion while moving. Although high-flex cables are designed to move, they aren’t made to withstand continual abrasion or friction when rubbing against other cables, hoses, cable tracks, or machine parts. The jackets and insulation of cables that don’t have flex ratings can quickly degrade.

What’s the solution?

Without exception, use high-flex cable with an outer jacket that’s abrasion-resistant. Materials and compounds used in outer jacket coatings are durable and flexible to prevent cracking, swelling, tearing, and general wear. This action can increase the wear life of your cable by many years.

#5: Improper cable selection. Selecting a flexible cable may appear to be a safeguard against automation system failure, but not all high-flex cables are created equally. Depending on design and construction, they can be manufactured to move in many ways. Some are made to be routed around corners or curves, and others are designed to tolerate continual twisting.

What’s the solution?

Make sure you have a complete understanding of your application’s requirements before selecting cable. Will it need to be bent around an object? Move back-and-forth? Material choices also affect cable performance, so make sure the stranding, conductor insulation, and jacketing material offer the necessary flexibility and lifespan. Cables with finely stranded conductors, for example, are better suited to large numbers of flexing cycles.

Have a question? We’re here for you with next-day delivery ex-stock and a dedicated technical support team! Send us an email info@schneider.co.il or give us a call 972-9-8924444 or drop us a note.

Alexander Schneider, Alpha wire’s exclusive distributor in Israel, provides experienced technical support and next-day delivery ex-stock for all wire & cable products.