Southwire CPB400 Plastic Conduit Bushing 4 Inch

Product Description

The SOUTHWIRE CPB400 is a 4-inch plastic conduit bushing designed to protect wire and cable insulation from abrasion where conduit terminates at an enclosure, panel, or junction box. The bushing threads onto the end of the conduit and provides a smooth, rounded interior lip that prevents conductor jackets from being damaged during pull-through. Electricians install this fitting as a standard step in any conduit termination that does not use a threaded hub with an integral throat. The lightweight plastic construction resists corrosion and makes handling simple on the job.

This bushing is suited for use in residential and light commercial electrical installations wherever 4-inch rigid metal conduit or intermediate metal conduit terminates at a box or enclosure. It is commonly installed in service-entrance work, feeder runs, and branch-circuit conduit systems. This part is also referenced as Topaz 840 and Madison CPB-400, making it a widely cross-referenced bushing used across multiple distribution channels.

Key Features

• 4-inch trade size fits standard 4-inch conduit terminations
• Plastic construction resists corrosion in damp and dry locations
• Smooth interior lip protects conductor insulation during wire pull
• Threads directly onto conduit end for quick installation
• Cross-referenced with Topaz 840 and Madison CPB-400

Compatibility

Compatible with 4-inch rigid metal conduit and intermediate metal conduit terminations. Also referenced as Topaz 840 and Madison CPB-400.

Installation Notes

Installation is performed by a licensed electrician in accordance with the National Electrical Code (NEC). De-energize the circuit and verify power is off before working inside any enclosure. Thread the bushing onto the conduit end by hand until snug before pulling conductors. Inspect the bushing throat for cracks or deformation before use, and replace if damaged.

Technical Specifications

• Trade Size: 4 inches
• Material: Plastic
• Weight: 0.1175 pounds
• Warranty: One Year Limited
• Country of Origin: China

Standard Information

• Brand: SOUTHWIRE
• Manufacturer Part Number: CPB400