Guide to Cable Shoes - Types, Installation, Uses, and Safety Tips

What Are Cable Shoes

Cable shoes, sometimes called cable cleats or cable clamps, are devices used to terminate and secure the ends of electrical cables. They provide a secure connection point and strain relief for cable conductors entering electrical enclosures like circuit breaker panels, motors, transformers, lighting fixtures, and junction boxes.

Key Features of Cable Shoes

There are several key features that characterize most cable shoes:

• Made of durable materials like aluminum, copper, bronze, or engineered composite polymers
• Have one or more holes for fastening screws or bolts to secure them in place
• Designed to withstand high temperatures in electrical systems
• Often feature teeth or serrated edges to grip jacketed cables tightly
• Exist in wide variety of sizes to accommodate cables from small branch circuits up to high ampacity feeders
• UL-listed for safety compliance with electrical codes

Why Properly Install Cable Shoes

Using the proper cable shoe for an application, and installing them correctly, provides several important benefits including:

• Safety - Securely anchors cable to reduce risk of shorts, arcs, fires from loose connections
• Reliability - Quality electrical terminations last for years without loosening or failing
• Reduced Maintenance - Cable shoes minimize loose connections needing re-torqued
• Professionalism - Installations look neat and workmanlike, impressing customers

Selecting the Correct Cable Shoe

Choosing the optimal cable shoe involves matching several attributes of the device to the wire and application:

Cable Jacket/Insulator Diameter

The cable diameter must closely match opening in shoe so that conductors make flush contact inside but jacket seals end off.

Conductor Size & Type

Shoe wire hole diameter and number must suit conductor gauge and be rated for that material like copper or aluminum.

Environment & Ampacity

Cable shoe composition and temperature/ampacity rating must be sufficient for currents in surrounding environmental conditions.

Mounting Orientation

Ensure cable shoe bolting orientation properly relieves mechanical stress on the terminated cable.

Codes & Certifications

Electrical inspectors look for listed cable shoes meeting UL and product safety standards for legal compliance.

Installing Cable Shoes Correctly

To yield safe and long-lasting cable terminations, electricians properly install shoes by following essential procedures:

Wire Insulation Stripping

Carefully trim back jacket and expose inner conductors to precise depth matching shoe depth to prevent shorts or uneven contact.

Conductor Cleaning

Thoroughly clean exposed wire strands with wire brush or abrasive to remove oxidation and ensure optimal conductivity with terminal.

Cable Insertion

Completely insert all wire conductor strands into cable terminal so they make flush, even contact at the base of the connection point.

Compression & Torque

Use manufacturer recommended tools to achieve torque specifications incompressing and mechanically securing shoe tails tightly together.

Anti-Oxidant Paste

Optionally apply a thin layer of joint compound to prevent corrosion-induced resistance at the wire-shoe junction as needed.

Common Cable Shoe Applications

Electricians widely use cable shoes across residential, commercial, and industrial electrical systems in locations like:

Breaker Panels

Secures incoming and outgoing feeder cables connecting to the main and branch circuit breakers.

Motors & Generators

Anchors high-ampacity supply cables feeding power to motors or connects output leads to generators collecting created electricity.

Transformers

Terminates cables conducting electricity into and out of transformers stepping voltages up or down as needed.

Junction Boxes

Provides safe enclosure cable entry points and splicing connections inside electrical junction boxes.

Inspection & Maintenance

Like all electrical devices, inspecting cable shoe terminations periodically and remediating any issues improves safety.

Look For:

• Loose or vibrating connections
• Corroded or oxidized terminals
• Heat discolored wires or shoes
• Insulation damage or shorts

Perform:

• Re-torque loose hardware
• Clean and reinstall oxidized parts
• Replace heat damaged components
• Rewrap or replace cables with damaged jackets

Following prudent cable shoe selection, installation, and maintenance practices reduces electrical system issues across installations.