Bridgeport Fittings 390 Insulated Grounding Bushing with Lug

Bridgeport Fittings 390 4" Insulated Grounding Bushing with Lug, Malleable Iron

The Bridgeport Fittings 390 is a 4" insulated grounding bushing with lug, built in malleable iron to deliver a secure, code-compliant ground path at conduit terminations. Designed for installations where rigid or intermediate metal conduit enters a box, panel, or enclosure, this bushing pairs an insulated throat with an integral grounding lug so contractors can protect conductor insulation and complete a reliable bonding connection in a single fitting. The malleable iron body stands up to the mechanical demands of conduit runs, making the 390 a practical choice for electricians who need a dependable grounding solution on commercial and industrial jobs. As a 4" size fitting, it is suited to larger feeder and service conduit terminations where a robust grounding bushing is required, making it a practical addition to a contractor's toolkit for grounding conduit systems.

Key Features

• Trade Size: 4" sizing is designed for larger conduit runs common in industrial and commercial feeder and service installations.
• Durable Construction: Malleable iron body resists impact, corrosion, and mechanical stress for long-term reliability on the job site.
• Insulated Throat: An insulated liner shields conductor insulation from abrasion and damage as wires pass through the conduit termination point.
• Integral Grounding Lug: A built-in lug provides a dedicated attachment point for a bonding or grounding conductor, simplifying installation and helping ensure a solid ground connection.
• Secure Conduit Termination: The malleable iron threads engage the conduit end firmly, helping keep the bushing and grounding connection in place under vibration and mechanical stress.
• Combined Insulation and Grounding: Integrating insulation with a grounding lug in one fitting reduces the number of separate components needed at each conduit termination.

Technical Specifications

• Refer to manufacturer documentation for complete technical specifications.

Typical Applications

• Conduit Grounding and Bonding
• Commercial and Industrial Electrical Installations
• Rigid and Intermediate Metal Conduit (IMC) Systems
• Panelboard and Enclosure Terminations
• Service Entrance and Feeder Conduit Runs
• New Construction and Renovation Electrical Projects

Why Bridgeport Fittings?

Bridgeport Fittings builds the 390 grounding bushing from malleable iron for the strength and durability that professional electricians expect from conduit hardware. Combining an insulated throat with an integral grounding lug in a single 4" fitting helps ensure conductors stay protected while grounding connections remain secure, supporting reliable, code-compliant electrical installations for commercial and industrial applications.