The Fuel Line Sets the Site: What to Check Before You Commit to a Standby Generator

Before you accept a standby generator, settle the fuel supply, the transfer path into your panel, the placement, and the load list in writing, then compare proposals line by line.

A standby generator is a large, fixed installation. Before you commit to one, settle four things in writing: the fuel supply, the transfer path into your panel, the placement, and the load list. Then compare the proposals against each other.

Check the fuel supply

Find out what the unit burns and where that fuel comes from. Ask whether the existing gas meter and line can carry the added load at full run, and whether the fuel supplier or utility must approve the connection. Ask who sizes the line and who confirms the pressure at the unit. A fuel question left open can keep the unit from running when you need it.

Trace the transfer path

The transfer switch connects the generator to your house. Ask where it will mount and which panel it feeds. Look at that panel's age and labeling before you accept a plan that adds circuits to an older board. The electrical panel service-life page gives the planning frame for the board the switch will tie into. Ask the installer to show the wiring route on a drawing you can keep.

Set the placement

Read the clearance requirements in the manufacturer's installation manual, and ask the installer to show them on your site. Check the distance to doors, windows, and vents, the ground surface, and the path for service access. Ask where the exhaust goes and how much noise the unit makes at the property line. Local rules may also set spacing, so ask who pulls the permit and what it covers.

Write the load list

List every circuit you want on backup, with the use of each. Keep the list within what the unit is rated to carry. Ask the installer to review the list against that rating and to write the result into the proposal. A load list nobody has checked is one you have not verified.

Compare the proposals

Put each proposal beside the others and read the scope, the fuel work, the transfer switch, the permit line, and the testing plan. Note what each proposal leaves out. Ask for the exercise schedule in writing, the start-up test, and who answers the phone after the install. Compare what is written, not what was said on the walk-through.