Parts of a Main Electrical Service
What is the Main Electrical Service, and why is it important?
Do you know how power enters your home? If not, you should—understanding how electrical power functions is key in protecting you, your home, and its contents. If you don’t know how something works, you won’t know what to maintain or when until it becomes a problem. In the case of your home’s electrical connection, ignoring such problems can turn into an emergency fast.
The main electrical service is what connects your main electrical panel to the power grid. It takes the electrical current from the utility company and steps it down to a level that the main electrical panel can handle. From there, the panel sends the power through your home. Without it, your home would not be able to receive power. This article will cover the parts of a standard above-ground main electrical service and distribution system commonly found in homes across the United States.
What are the parts that make up the Main Electrical Service?
Service Drop (aka Service Line)
The service drop includes the wires and metal cable that connect to your house from the transformer. This is made up of a neutral line connected to the transformer and two 120V lines of opposite phase. These two 120V lines can be recombined on specific circuits in the electrical panel designed to handle 240V. This allows for electricity to safely enter the house while also allowing you to power appliances that need 240V to function, like your dryer. (https://en.wikipedia.org/wiki/Split-phase_electric_power)
The section of the service and grounded neutral wires that are made to curl around below the weatherhead before entering it helps keep water out. The water is forced to drip from the bottom of the curve due to gravity. Without this, the water could potentially flow into the weatherhead and your electrical panel. Since water is an easy conductor, it could become electrified, potentially electrocuting you or starting a fire. Needless to say, the drip loop is an important safety feature that should not be overlooked.
Weatherhead (aka Service Head, Weathercap, Service Entrance Cap)
This cap keeps water out of the pipes where the service wires and grounded neutral wire enter. The weatherhead can either be mounted to a mast or to the building itself. It is shaped like a hood with the wires entering it from a roughly 45-degree angle. To further protect the weatherhead from water, there is a rubberized gasket in place that forms a tight seal against the wires. Weatherheads are only used for low voltage situations such as residential homes and are required by building codes to ensure the safety of your home.
Pole that contains the service wires and grounded neutral wire. It generally attaches to the meter box and feeds the wires through it. The mast’s rating is relative to the amperage of the service coming in. If you have a 100 amp service and want to upgrade to 200 amps, you will need to replace it with a mast rated for at least 100 amps.
Meter Box (aka Meter Can or Meter Base)
This is the housing used to protect the meter socket and service wires. While the meter box is often attached to the side of the house, it may also be attached to the utility company’s power pole.
This is a watt measuring device that tracks your power consumption month to month. Older meters have numbered dials, while most newer meters have digital displays. Many of these new meters can even be read directly from the utility company’s office. Like the mast, the meter socket is rated for the amperage coming into the house. If you plan to upgrade, you will have to replace this as well.
Service Disconnect (aka Safety Switch or Weatherproof Disconnect)
This connects below the meter box and is a safety switch that allows you to disconnect the utility company’s power without going to the electrical panel. This is especially important in case of fire, allowing firefighters to douse the flames without fear of electrocution or in the case of natural disasters.
Main Electrical Service Panel
Suppose you could consider the main electrical service to be the vascular system of your home. In that case, the main electrical service panel is its heart and brain. Your electrical panel breaks down the power coming in and sends it through its circuits to the many sockets and switches in your home. Circuit breakers are used to monitor each of the circuits, and if they detect too much power, they will trip, cutting power from the circuit until it is turned back on. It would be an understatement to say that proper maintenance of your electrical panel is important. Like many other main electrical service parts, the parts of your electrical panel will wear out over time. Failing to replace these parts could lead to a failure of the circuit breakers, which in turn could start a fire.
The ground wire links the electrical service to the grounding electrodes or water pipes.
Grounding Electrodes (aka Grounding Rods)
These are generally eight to ten-foot-long copper rods inserted into the ground. They connect the Main Electrical Service to the ground by way of the ground wire and dissipate dangerous overvoltage. If the outside wiring were to be struck by lightning, this grounding would protect the house by directing the voltage into the earth, where it would dissipate. One is also connected to the main water line to ensure that the water does not become electrified.
Common Ways Your Main Electric Service May Be Damaged
Unfortunately, the parts of your main electrical service are not impervious to damage or wear over time. Here is a list of common ways your service may be damaged.
Fallen Trees or Branches
This is the most common way that damage occurs to service masts. A tree or branch either hits the mast itself or the service lines. This could bend the mast, damaging the lines inside or even completely disconnect them. To avoid this sort of damage, make sure to trim nearby trees back as much as possible.
Hail is the main culprit here, as heavy hail can severely damage many of the main electrical service components. Debris whipped up by the wind can also impact the mast and other parts such as the meter box and socket.
Heavy wind can bend the service mast or damage the service drop and the mast’s connections, especially as it ages. This could cause the mast to bend or buckle. Heavy wind can also cause the mast and meter to pull away from the house.
The most common power surges that could damage your service are those that happen during storms. A direct lightning strike to the power line or pole could send a huge amount of excess voltage to your service connection. If the surge is big enough, it could completely fry all of the conductors in your main electrical service. If you lose power during a storm and it doesn’t turn back on when your neighbors start to, consider the possibility that a surge damaged your service.
Who is in charge of repairs?
It is also essential to know that some parts of the main electrical service fall on the customer to furnish and maintain. Others belong to the utility company and are maintained by them. In general, the customer owns and pays to maintain the weatherhead, mast, meter box, disconnect, and grounding. The company owns and pays for the service drop, service connection, and meter socket. However, this can differ from company to company, so make sure you check with them to be certain.
While it is on the customer to maintain and repair the parts mentioned previously for the main electrical service, never try to make repairs on your own. Always hire a professional to make any repairs, maintenance, or installations. On your own, attempting to do so can be highly dangerous as the service wires are always live and could electrocute you. In order to minimize the need for emergency repairs, we recommend that you have your main electrical service evaluated yearly to ensure everything is in good shape.
For more information on your main electrical service or to schedule an appointment to have it evaluated, give our friendly office team a call today at 618.993.HELP . Alternatively you can book online using the handy button above.
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