If your home receives power through overhead wires, you have a service mast and a weatherhead, even if you have never noticed them. These parts carry the electrical service from the utility line to your home and keep water out where the wires enter. They are a key part of an overhead electrical service, and understanding them helps you recognize when they need attention.
Here is what a service mast and weatherhead are and what they do.
The service mast
The service mast is the vertical pipe, or conduit, that carries the service entrance conductors up and above the roofline. On homes with overhead power, the utility’s wires connect at a high point so they have proper clearance over the yard, driveway, and roof. The mast provides that height and supports the connection point where the utility’s service drop meets your home’s wiring.
The mast has to be sturdy, because it holds up against the tension of the overhead wires and the weather.
The weatherhead
At the top of the service mast is the weatherhead, also called a service head or service entrance cap. This fitting is where the service conductors exit the mast to connect to the utility’s wires. Its job is to keep water out. The weatherhead is designed with a downward-facing, hooded shape so that rain runs off rather than into the conduit, and the wires form a drip loop so water drips off the low point instead of following the wires into the mast.
Together, the mast and weatherhead deliver power to your home while keeping the weather out of your electrical system.
Overhead versus underground service
The service mast and weatherhead are specific to overhead service, where power comes from utility poles by aerial wires. Homes with underground service, where power comes through buried conductors, do not have a mast or weatherhead. Whether you have overhead or underground service depends on your neighborhood and home.
When a mast or weatherhead needs attention
These components are exposed to the weather and the pull of the overhead wires, so they can be damaged over time or in storms. Signs of trouble include:
- A mast that is bent, loose, or pulled away from the house
- A damaged or missing weatherhead
- Corrosion or visible wear
- Damage from a fallen limb or storm
A damaged service mast or weatherhead is a serious issue, because it involves the live service conductors and can let water into the system. This is not a do-it-yourself repair. It requires a licensed electrician and coordination with the utility, since the service may need to be disconnected to fix it safely.
A service mast is the vertical conduit that carries your overhead service conductors up above the roofline, and the weatherhead is the fitting at the top that keeps water out where the wires exit. Together they bring power to homes with overhead service while protecting the system from the weather. Because they involve live service conductors, any damage or repair should be handled by a licensed electrician in coordination with the utility.
Stella Electric repairs and upgrades service masts, weatherheads, and service equipment for homeowners across the Baltimore area and throughout Maryland, with flat-rate pricing and no overtime charges. If your service mast or weatherhead is damaged, we can help. Financing is available on qualifying projects.
