Image Credit: Americor | Digi-Key

 

 

Cable clamps are accessories for wire and cable.  They are used to bundle, clip, clamp, label, guide, and protect wires and cables. Clamps play an important role in the installation and maintenance of cable systems. Cable clamps are used in home construction, automotive, rigging, and many more industrial and manufacturing applications. The clamps are available in a wide variety of types and sizes.

 

Types of Cable Clamps

There are four common types of cable clamps: U-type, edge, parallel, and J-type.

  • how to select cable clampsU-type- The U-shape clamps are also called right-angle clamps. The support is attached directly to a steel beam via bolts that are threaded and fastened to a flat or curved top piece. U-type clamps are generally used when the conduit (pipes though which electrical power cables can be run) needs to be installed perpendicular to the beam. Bend type clamps, such as U-type, are not recommended for wire bundles over 1" diameter as the weight of the wires may exceed the structural capabilities of the clamp. Image Credit: Digi-Key
  • how to select cable clampsEdge- Edge clamps can attach conduits to the thin edge of steel beams by using jaws to clamp down tightly on the conduit. They are well-suited for perpendicular installations. When selecting an edge clamp it is important to consider the weight the clamp can support per 100 units of distance. Image Credit: Grainger
  • how to select cable clampsParallel- Parallel clamps have two jaws: one holds the conduit in place and the other, thinner jaw attaches to the steel beam. Parallel clamps are best used when the conduit runs parallel or along the length of the steel beams. Image Credit: Grainger
  • how to select cable clampsJ-hook- J-hook cable clamps have a unique 'J' shape which hook around the conduit. The conduit is mounted on the inside, and then the threaded top of the clamp is attached to the steel beam with a nut or bolt.  J-hook cable clamps can be used for parallel and perpendicular applications since the conduit is set directly on the beam. Image Credit: Panduit

Cable Clamp

Opening Size

Load Rating

U-Type

½ inch to 4 inches

30lbs- 330lbs

Edge

½ inch to 3 inches

Depends on number of clamps per 100 units of spacing

Parallel

½ inch to 4 inches

30lbs- 330lbs

J-Type

Varies

Varies

 

Product Specifications

Cable clamps often come in a variety of colors and sizes for different applications.  Important specifications to consider when searching for cable clamps include:

 

how to select Cable clampshow to select cable clampshoe to select cable clamps

Various shapes of cable clamps: V-Type | Saddle clip | Half-clamp

Image Credit: Richco | Digi- Key | Digi-Key

  • The shape and size of the item or system being secured. The maximum diameter refers to the maximum diameter of the bundle of wires and cables. If the clamp is larger than the conduit foreign matter can enter the space between the two pieces can cause damage due to abrasion. If the conduit is larger than the clamp deformation and strain can occur on the mounting foot of the clamp and potentially break the clamp. A good rule of thumb is to use 25 lb. minimum tension for conduits where no movement is desired and a 10 pound maximum tension where movement is required.   
  • Environmental considerations include:
    • Temperature range- The full, required range of ambient operating temperature. Also important to note is if the temperature will vary or if it is continuous.
    • Presence of surrounding fluid-The type of fluid in the system is important as well as if the clamp will be immersed in or splashed by this fluid.
  • Vibration shock in the area.
    • If the area of use is interior or exterior.
  • Structural considerations include:
    • The available mounting area and clearance - To provide the best structural advantage the clamp mounting should be located to the inside of the bend.
    • The position of the mounting (inverted, horizontal, vertical)-  The clamp and conduit should always be at 90° at installation. This will prevent built-in preload, and clamp distortion and failure. When mounting conduits to a vertical structure, the bolt should be above the conduit so the static force does not oppose the mounting foot.
    • The external forces such as a line surge or structure flex- The conduit should be supported as close to the conduit bend as possible. Image Credit: Esterline.com

    • The size of stud or bolt used for mounting
    • Potential damages due to abrasion or galling
  • Installation  considerations include:
    • If the clamp will be installed prior to the installation of the conduit or wire bundle.
    • If the clamp will be placed on the wiring or conduit prior to installation.
    • If the clamp and conduit will be wired simultaneously.
  • Strain reliefs protect the lifeline of your electric products by absorbing the forces of push and pull that may be exerted on the flexible wires, cables, or tubing. 

Cable Clamp Standards

Common approvals for cable clamps include

  • UL Listing Mark, and UL Recognized Component Mark (US and Canadian) - The UL Listing Mark denotes that Underwriters Laboratories Inc. (UL) has found that samples of the product met UL's safety requirements. These requirements are primarily based on UL's published Standards for Safety.  UL Recognized Component Marks are used only on component parts that are part of a larger product or system. These components may have restrictions on their performance or may be incomplete in construction. Products intended for Canada carry the Recognized Component Mark "C."
  • The CSA Mark may appear alone or with indicators. If it appears alone, it means that the product is certified for the Canadian market, to the applicable Canadian standards. If this Mark appears with the indicator "C and US" or "NRTL/C" it means that the product is certified for both the U.S. and Canadian markets, to the applicable U.S. and Canadian standards. 

References

Clamp Installation Guide

 


Related Products & Services

  • Cable Ties

    Cable ties hold groups of cables together for support and ease of maintenance.

  • Shrink Tubing

    Heat shrink tubing conforms to the size and shape of wires, connections, open coils, and other electrically conductive elements to insulate and protect them from adverse environmental conditions.

  • Strain Reliefs

    Strain reliefs protect the lifeline of electrical products by absorbing the forces of push and pull that may be exerted on the flexible wires, cables, or tubing.