Service Entrance Caps

How to Choose Service Entrance Caps & Weatherheads

A service entrance cap sits at the top of an overhead service raceway and provides the transition where service conductors leave the mast toward the utility connection. The correct weatherhead needs to match the raceway trade size and installation method while remaining suitable for exterior exposure. It also has to leave a practical conductor path without becoming a substitute for the structural, electrical, or utility requirements of the rest of the service entrance.

• Building the raceway around the service head? Compare conduit fittings and connectors.
• Need related raceway hardware? Review electrical fittings.
• Coordinating the service grounding system? Start with grounding and bonding hardware.

Match the Service Entrance Cap to the Raceway Trade Size

Trade size is the first specification to confirm. The service head has to connect to the raceway or mast it is designed for, so a cap intended for one nominal conduit size should not be selected because its opening merely appears close to another size.

For example, a service mast using 1-1/4 in raceway needs a cap identified for that trade size and connection method. Decision rule: establish the service raceway type and trade size first, then choose the service entrance cap. Related connectors, couplings, and transition hardware can be coordinated through Lumera’s conduit fitting selection.

Service Head Orientation Should Support the Conductor Path

The cap is where conductors transition from the protected raceway to the overhead service connection. Its openings and installed orientation therefore need to work with the planned conductor route while helping limit water entry into the raceway. The conductor arrangement should follow the exact fitting instructions and the service design rather than being forced through an inconvenient opening.

On an overhead service where the utility connection approaches from one side of the building, the raceway and service head should be laid out before conductor lengths are finalized. If additional protection is required where conductors pass a raceway edge or termination point, check the appropriate conduit and grounding bushings for that separate function.

Choose Material for Outdoor Exposure and the Complete Raceway System

Service entrance caps operate outdoors, so material compatibility and environmental suitability matter. Metallic and nonmetallic fittings can have different connection methods and exposure limitations, and material should be considered with the raceway rather than as an isolated finish choice.

A fitting installed on an exposed service mast will see sun, moisture, and changing temperatures throughout its service life. Decision rule: use a product identified for the actual outdoor application and compatible with the raceway it terminates. Lumera’s broader electrical fittings category can be used to coordinate the surrounding hardware by material and size.

Do Not Treat the Weatherhead as Structural Support for the Service Drop

The service entrance cap finishes the raceway termination; it does not by itself establish the mast’s structural capacity or utility attachment requirements. Service masts, attachment points, conductor clearances, and overhead service-drop geometry need to be planned as one system.

For a mast extending above a roofline, the structural and utility requirements can be more important than the cap itself. Confirm the project drawings, utility requirements, and applicable installation rules before finalizing the assembly. Lumera’s service entrance components guide explains where the weatherhead sits in the sequence from the utility connection to the service disconnect.

Coordinate Grounding and Bonding With the Complete Service

The weatherhead does not replace grounding or bonding hardware elsewhere in the service entrance. Metallic raceways, service equipment, grounding electrode conductors, and other conductive parts can have separate bonding requirements depending on the equipment and wiring method.

If the project includes a service upgrade, review those connections at the same time rather than treating the new cap as the only fitting change. Lumera’s grounding and bonding collection covers clamps, lugs, bushings, and related connectors selected by conductor, connection point, and environment.

Verify the Existing Service Before Ordering a Replacement Cap

Replacement work should begin with the existing raceway size and condition, not the dimensions of the old cap alone. Prior alterations, corrosion, mismatched fittings, or damaged raceway can make a like-for-like visual replacement the wrong solution.

Before replacing a service head, record the raceway trade size, material, attachment method, conductor arrangement, and surrounding mast condition. Service conductors and utility connections create hazards that are different from ordinary branch-circuit work. Installation should be handled by qualified electrical personnel and may require utility coordination before the service can be safely worked on.

Ordering Service Entrance Caps for a Project

For service upgrades, multi-unit work, maintenance inventories, or repeated installations, organize the material schedule by raceway trade size, raceway type, cap material, mounting method, outdoor exposure, and quantity. Keep related conduit fittings and grounding components tied to the same service location so mismatched sizes do not arrive at the jobsite.

Request a Service Entrance Project Quote

For larger quantities or projects involving several service assemblies, request a project quote after the overhead service requirements have been verified.

Have these details ready:

• Service raceway trade size
• Raceway type and material
• Required service entrance cap configuration
• Existing or new-service installation
• Outdoor exposure and environmental conditions
• Related connectors, couplings, or bushings
• Grounding or bonding hardware requirements
• Required quantity

For projects with several service locations, you can also submit your service fitting schedule so each cap remains matched to the correct raceway and associated hardware.

Service Entrance Cap FAQs

Is a service entrance cap the same as a weatherhead?

Yes. “Service entrance cap,” “service head,” and “weatherhead” are commonly used for the fitting at the top of an overhead service raceway where service conductors exit toward the utility connection. Lumera’s service entrance guide identifies the weatherhead as this component in an overhead service assembly.

How do I know what size service entrance cap I need?

Match the cap to the nominal trade size and type of the service raceway. Do not size it by measuring only the outside of the existing fitting. Verify the raceway first, then select compatible hardware. Lumera’s conduit fittings can be coordinated with the same raceway size where additional connectors or couplings are required.

Does a weatherhead make the service mast waterproof?

A weatherhead is designed to help limit rainwater entry at the top of the service raceway, but it does not make every part of the service assembly waterproof. Its orientation, conductor arrangement, raceway connections, and other exterior components still need to be properly installed and suitable for the location.

Can I replace only the service entrance cap?

Sometimes the cap is the only component requiring replacement, but the surrounding mast and fittings should still be inspected. Damage, corrosion, incorrect raceway sizing, or other service changes can require more than a new weatherhead. If related fittings also need replacement, use the electrical fittings category to coordinate compatible parts.

Who should install a service entrance cap?

Service entrance work should be performed by qualified electrical personnel. The conductors are located at the utility-service boundary, and the project may require utility coordination, permits, inspections, or disconnection procedures. Before changing the cap or mast, confirm who is responsible for each part of the service and how the utility requires the work to proceed.