Can a generator interlock work with every electrical panel?

No. A generator interlock must match the panel’s construction, breaker layout, and approved equipment combination. An incompatible kit may not control breaker movement correctly.

Does a generator interlock start a portable generator automatically?

No. A generator interlock coordinates breaker positions, but it does not start or stop a portable generator. The generator remains a manually operated source unless separate equipment provides automatic control.

What part connects a portable generator to the panel?

A generator inlet provides the connection point for the portable generator cord. The inlet feeds the panel through the dedicated generator breaker associated with the interlock.

Glossary

What Is a Generator Interlock?

A Generator Interlock is a mechanical device installed on an electrical panel that controls the position of the main and generator breakers. The interlock allows only one power source to feed the panel at a time. This arrangement helps prevent utility power and portable generator power from connecting to the same panel simultaneously.

Quick Facts About Generator Interlock

Key Takeaways About Generator Interlock

A sliding or pivoting mechanism links two panel breakers.
The panel accepts generator power through a designated inlet.
An interlock is not the same as an automatic transfer switch.

How Generator Interlock Works

A worker in a blue cap points at an open electrical panel while talking to another man in a workshop

A Generator Interlock mounts to a compatible electrical panel and links the main breaker with a dedicated generator breaker. The mechanism permits one breaker to remain in the operating position while blocking the other. A generator inlet connects the portable generator to the panel through the generator breaker.

Related glossary terms: Backfeed, Panelboard, Circuit Breaker.

During a utility outage, the panel operator follows the equipment sequence to connect generator power to selected circuits. When utility service returns, the generator connection is removed before normal panel operation resumes. A transfer switch performs a similar source-selection task through a separate switching device, often with automatic operation. Panel design, breaker arrangement, and generator connection method determine whether an interlock fits the installation.

A hand flips a labeled generator transfer switch inside an electrical breaker panel

From the Chris Miller Electric team

When we work on backup generator installation, we check that the interlock matches the panel design and the generator connection. We inspect breaker movement, inlet wiring, labeling, and the panel enclosure. Our team also verifies that the selected circuits align with the generator’s intended use.

Generator Interlock in Practice: A Real-World Example

A homeowner wants portable generator power for selected household circuits during an outage. A generator interlock on the main panel coordinates the utility and generator breakers, while an exterior inlet provides the generator connection point.