Can a service disconnect be located outside?

Yes, a service disconnect can be outside the building. An outdoor disconnect sits in an enclosure designed for its surroundings and may be near the electric meter.

Does a service disconnect protect against overloads?

A service disconnect may provide overload protection if it includes a suitable breaker or fuses. A switch that only opens the circuit doesn't provide that protection.

How is a service disconnect labeled?

A service disconnect may have a label that identifies its purpose. The handle or enclosure may also show which position is on and which is off.

Glossary

What Is a Service Disconnect?

A service disconnect is a switch or breaker that shuts off power from the utility service to a building's electrical system. It sits at the point where power enters the system. Depending on the setup, the disconnect may be part of a panel or housed in a separate enclosure.

Quick Facts About Service Disconnect

Category: Service equipment
Used for: Shutting off service power
Common confusion: Branch circuit breaker
Also called: Main Disconnect, Service disconnecting means
Often discussed with: Electrical Panel Upgrade, Electrical Panel Repair

Key Takeaways About Service Disconnect

A branch breaker controls a smaller part of the electrical system.
The disconnect's location depends on the electrical setup.
Turning it off doesn't make utility-side wires dead.

How Service Disconnect Works

A person disconnects a red wire from a gray service box mounted on a brick wall

A service disconnect opens the path that carries power into the building's electrical system. Moving its handle to the off position opens that path. Moving the handle back closes the path and lets power flow again.

Related glossary terms: Breaker Panel, Circuit Breaker, Grounding.

The disconnect differs from a circuit breaker serving a branch circuit. A branch circuit supplies a smaller area or a particular appliance. The service disconnect controls power to the system fed through the service equipment.

The utility-side wires can remain energized even when the disconnect is off. Equipment connected on the utility side may also remain energized. A disconnect handle's position alone doesn't prove that every wire in the enclosure is dead.

Hands use a screwdriver inside a labeled electrical disconnect box mounted on a brick wall

From the Chris Miller Electric team

When we plan an electrical panel upgrade, we check the existing service disconnect and its connection to the panel. We also look at the enclosure and the space around the equipment. Those details help us plan how the upgraded panel will connect to the service.

Service Disconnect in Practice: A Real-World Example

A homeowner is replacing an older breaker panel during an electrical panel upgrade. The existing service disconnect sits in a separate enclosure, so the panel plan accounts for that connection.