Choosing a location for your new standby generator is usually straightforward, but there are factors you must consider. A good location is one that allows the generator to operate efficiently and safely without endangering the lives of people living in the house. Always install standby generators outdoors on stable ground that does not flood. The exhaust gases produced by a generator contain deadly carbon monoxide, and that is yet another consideration for location.
Consult your local building code authority for necessary requirements and permits. They have the final say in all electrical and plumbing installations, and local ordinances may vary from standard codes and will often supersede the manufacturer’s recommendations. Experienced electricians and plumbers know how to work with local building departments to resolve conflicts between installation instructions and local building codes.
Minimize costs by placing the generator as close to the existing electrical service entrance as possible without getting too close. Gas and electric utility companies require specific clearances between their equipment and the equipment belonging to other companies or the homeowner. This is one way your local code authority can help ensure you place your generator correctly. If your generator will operate on LP gas, there is a minimum distance to maintain from the tank’s fill valve which varies by locality.
Some general guidelines include placing your generator where prevailing winds will blow the exhaust away from the home. Keep the generator away from bedrooms, living areas, and where the noise won’t bother your neighbors. All locations must be at least five feet away from openings such as windows, soffit vents, and doorways. Never locate the generator under an overhang, in a breezeway, or in recesses blocked by trees, shrubs or other vegetation. Avoid areas subject to snow drifts and protect the generator from pets, animals, people, and traffic.
Standard required clearances include three feet from any wall, five feet from any house opening, three feet from flammable materials. Never locate the generator anyplace that might allow exhaust gases to accumulate, under a roof of any kind, or inside any kind of building.
After you’ve selected a location, have it approved by your local code authority. There’s nothing worse than purchasing materials and installing them, only to have your code inspector fail your installation because it didn’t meet local codes for placement. It wastes time and money.
Some localities require a concrete pad for the generator to sit on, others allow generators to sit directly on a bed of gravel or pea gravel. Most manufacturers supply their generators in an enclosure that includes a suitable base for the generator―provided the underlying surface is level.
A bed made from compacted sand with pea gravel on top makes a good pad. Remove the sod and dirt to make a rectangular shaped hole as large as required and six inches deep. Add a three-inch layer of damp sand and compact it. Make a 2-by-4 frame from cedar or pressure treated lumber to help enclose the gravel and keep it on the pad, and out of your grass. Level the frame with a spirit level, fill it with pea gravel, and you’re ready to set the generator on it.
Even when local codes require a concrete pad, it is still a good idea to build a base of compacted sand and set a frame on top of it. Level the frame and fill it with concrete. Once it hardens and cures, it’s ready for the generator.