What fuel can a standby generator use?

A standby generator may use natural gas, propane, or another approved fuel source, depending on its design and the property's available supply.

Can a standby generator power every circuit in a building?

A standby generator can power every circuit only when its capacity, wiring, and transfer equipment are designed for the building's total electrical load.

What causes a standby generator to fail during an outage?

A standby generator may fail because of a weak starting battery, control fault, fuel problem, damaged wiring, or a transfer switch that does not operate correctly.

Glossary

What Is a Standby Generator?

A standby generator is a permanently installed backup power system that starts automatically when utility power fails. It uses an engine to produce electricity and connects to selected building circuits through a transfer switch. Standby generators can support essential equipment, appliances, or broader electrical loads, depending on system design and available capacity.

Quick Facts About Standby Generator

Key Takeaways About Standby Generator

It remains installed and ready for automatic operation.
A transfer switch connects backup power to selected circuits.
It is not the same as a portable generator.

How Standby Generator Works

Hands position a small white backup generator on a wooden desk beside a brochure and laptop

Standby generator systems monitor the building's utility supply through an automatic control system. When the utility source fails, the generator engine starts and produces electrical power. A transfer switch then moves connected circuits to the generator supply. When utility power returns, the system transfers the circuits back and stops the engine.

Related glossary terms: Automatic Transfer Switch, Critical Loads, Load Calculation.

Electrical capacity determines which loads the system can support. A smaller installation may serve selected circuits, such as refrigeration or heating controls. A larger system may serve most of a building's electrical panel. Proper operation depends on compatible wiring, fuel delivery, controls, grounding, and regular inspection.

A technician tests an open generator beside electrical gear, tools, a lit bulb, and a laptop outdoors

From the Service Electric team

When we inspect a standby generator, we check the power source, transfer switch, wiring connections, controls, and connected loads. Our team also looks for signs of failed starting components, loose terminations, fuel-related issues, or fault codes that could prevent reliable operation during an outage.

Standby Generator in Practice: A Real-World Example

A homeowner loses utility power during a storm. The standby generator starts automatically, and the transfer switch supplies the connected refrigeration and heating circuits while the utility service remains unavailable.