03. What is the difference between non-rigid and rigid cable cleats?

The left photo of legacy non-rigid cable cleats was taken 1.3 msec after the initiation of a 111 kA_PEAK 3-phase short circuit test on single conductor 500 kcmil cables in cable tray.  The right photo depicts Talon® cable cleats during a similar short circuit test (i.e. 121 kA_PEAK on same cables with identical lineal cable cleat spacing and photo timing).  The rigid design of Talon® cable cleats limits cable deflection and restrains cables subject to axial, lateral and torsional forces.  Additionally, Talon® cable cleats successfully passed the IEC 61914 axial resistance test after multiple short circuit tests.

One characteristic of non-rigid cable restraints is their increased propensity to deform under mechanical stress.  Cable restraints, including cable cleats, are classified as “non-rigid” when manufactured from ductile materials (e.g. metal banding) that can deform significantly and permanently when exposed to static or dynamic cable forces.  The left photograph demonstrates the severe limitations of non-rigid cable cleats.

Cable cleats classified as “rigid” retain their physical shape when exposed to static and dynamic mechanical stresses.  Rigid cable cleats are typically manufactured from non-ductile materials (e.g. heavy metallic cross-section or reinforced thermoplastic).  Thick stainless steel cross-sections are impractical due to high cost and other metals are unrealistic due to localized induction heating, corrosion susceptibility and/or poor product designs.  Fortunately, due to technological advances in non-metallic materials and their natural immunity to galvanic corrosion, cable cleats manufactured from high-strength reinforced thermoplastics are rapidly replacing legacy products.  Talon® cable cleats utilize a high-strength interlocking frame that simultaneously encloses cables and a support rung and do not suffer permanent deformation during testing.