Southwire 53151-S-UPC Square Box Extension Ring

Product Description

The SOUTHWIRE 53151-S-UPC is a drawn steel square box extension ring designed to increase the wiring capacity of existing 4-inch by 4-inch square junction boxes. Licensed electricians add this ring to an existing box when additional wiring space is needed, eliminating the cost and labor of removing and replacing installed conduit boxes. The ring also opens access for additional conduit runs and electrical conductors, making it a practical solution during service upgrades, panel additions, or circuit expansions. It carries UL listing and meets RoHS compliance requirements.

This extension ring is suited for residential and light commercial electrical installations where existing 4-inch square junction boxes have reached capacity. Electricians use it during retrofit work, tenant improvements, or any project requiring added conductor fill without disturbing existing conduit terminations. It is sold individually and fits standard 4-inch by 4-inch square box configurations commonly found in both new construction and older wiring systems.

Key Features

• Increases wiring capacity of existing 4-inch by 4-inch square junction boxes without box removal
• Provides access points for additional conduit runs and electrical conductors
• UL listed for safety compliance in electrical installations
• RoHS compliant construction
• Drawn steel construction for consistent dimensional fit
• Lightweight at 0.525 pounds, reducing handling time during overhead or confined-space installs

Compatibility

Designed as an OEM-style replacement and add-on component for standard 4-inch by 4-inch square electrical junction boxes used in residential and light commercial wiring installations.

Installation Notes

Installation should be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and applicable local codes. Always de-energize the circuit and verify absence of voltage with a meter before opening any junction box. Secure the extension ring to the existing box using the appropriate mounting screws before pulling or terminating any conductors. Ensure total conductor fill does not exceed the combined cubic-inch capacity of the box and ring per NEC fill calculation requirements.

Technical Specifications

• Box Size: 4 inches x 4 inches
• Weight: 0.525 pounds
• Certifications: UL Listed, RoHS Compliant
• Unit of Measure: Each

Standard Information

• Brand: SOUTHWIRE
• Manufacturer Part Number: 53151-S-UPC