What is a service entrance cable?

The Service Entrance Cable is the "bridge" connecting the main power grid to your home.
If you imagine the city's power grid as the main pipes of a waterworks, then the Service Entrance Cable is like the main water pipe that runs from your door meter into your kitchen and bathroom. It's the first formal barrier for electricity to enter the building.

1. Its Core Function

It's the connection between the power company's wires (usually on utility poles or underground) and your home's main electrical panel (circuit breaker panel). Its primary task is to safely transmit the electricity distributed from the high-voltage grid to your home's distribution system center.

2. Common Appearances and Classifications

On the wire and cable extruder production line, this cable is typically manufactured in two main forms:
SER (Service Entrance Round): It's round. This cable contains a live wire, a neutral wire, and a ground wire. It's very flexible and often used to connect from the main meter to various auxiliary electrical panels in the home.
SEU (Service Entrance Unarmored): It's flat. This design lacks a separate ground wire and is typically used only for the section connecting the outdoor utility pole to your meter box.

3. Its Structural Composition

Because this cable carries the power for the entire building, it's much thicker than a typical socket wire:
Inner Core (Conductor): Usually made of multiple strands of aluminum alloy or copper wire twisted together. Because it carries a large current, the core wires are very thick.
Insulation Layer: During wire and cable extruder processing, a thick layer of plastic (such as polyethylene) is wrapped around the inner core to prevent leakage.
Protective Outer Sheath: The outermost layer is a gray, UV-resistant, moisture-proof, and fire-retardant plastic sheath. Even after years of exposure to the elements outdoors, it won't easily crack.

4. Why is it Important?

It's the section of wire before the main power switch in your home. If this wire is of poor quality or improperly installed, all the appliances in your home will malfunction. Therefore, power companies and renovation workers have very strict requirements on the thickness (specification) and wear resistance of this type of cable.