When Cable Fights Back
Cable naturally retains the curved shape formed during packaging and transport, which, if not properly addressed before installation, can result in tension inconsistencies, recoil, or sagging—particularly in extended horizontal or overhead runs. To ensure a reliable deployment, best practices focus on fully relaxing the cable prior to routing, applying controlled tension during pulls, and providing consistent support throughout the run, all of which are critical steps to maintain cable integrity and long-term performance.
To translate these considerations into effective action, the following best practices detail the essential steps for managing cable memory and tension to ensure durable, code-compliant installations.
Cable Memory & Tension Issues
- Understand Cable Memory
What It Is: Cable memory is the retained coil shape from packaging or transport. If not fully relaxed before installation, it can cause spring-back, uneven tension, or sag—especially in long horizontal runs or overhead pathways.
Why It Matters: Unrelaxed cable can cause mechanical stress, sagging, and signal degradation.
Best Practice: Fully unwind and allow cable to rest before installation, particularly in cold environments. - Manage Tension and Sag
Why It Matters: Improper tension leads to stress on connectors and terminations, sagging cable paths, and increased risk of abrasion or signal loss.
Best Practice: Apply consistent, moderate tension when pulling cable and support cable frequently using J-hooks, D-rings, or brackets to prevent sag. - Control Snapback and Recoil Hazards
Why It Matters: Sudden release of tension in overhead runs can cause snapback, risking injury and cable damage.
Best Practice: Anchor one end securely before releasing tension and handle cable carefully to mitigate recoil risks. - Monitor Cable Twist
Why It Matters: Twisted cable indicates uneven tension or residual memory, which can compromise performance.
Best Practice: Detect and correct twists by repositioning or re-pulling cable as needed. - Adapt to Jacket Material and Environment
Why It Matters: Different jacket materials and temperature conditions affect cable flexibility and memory retention.
Best Practice: Allow longer rest for stiffer cables (e.g., PVC in cold) and store cable in temperature-controlled staging areas before installation. - Follow Standards and Manufacturer Guidelines
Why It Matters: Compliance ensures cable integrity, performance, and safety.
Best Practice: Adhere to NEC 800.24, TIA/EIA-568, and specific cable manufacturer tension and support recommendations.
Installer Insight
A cable that “wants to go back to the box” is signaling insufficient relaxation and support. Give the cable adequate rest time, handle it with controlled tension, and secure supports at close intervals to ensure a stable, reliable installation.
By addressing cable memory with disciplined handling and tension control, installers can prevent costly setbacks and lock in a stable, standards-compliant infrastructure from the very first pull.
This guide is intended for informational and reference purposes only. It does not supersede local codes, manufacturer specifications, or the judgment of the Authority Having Jurisdiction (AHJ). Installation practices must always be verified against current NEC, ANSI/TIA standards, and site-specific requirements. Winnie Industries products must be installed and used in accordance with official instruction sheets or designated training. Products should never be applied beyond their intended purpose or in a manner that exceeds specified load ratings. Proper fastening is critical to system integrity and functionality, requiring secure attachment to structurally sound components capable of supporting imposed loads. All installations must comply with governing codes, regulations, and job site requirements. Always consult your AHJ for specific regulatory guidance.