Why a generator needs a permanent base
A standby generator is an engine that starts itself, and it has to sit level and still for years. Set on loose fill beside the house, it settles with every monsoon season the same way an AC condenser does, and the gas and electrical connections take the strain. A concrete pad on a compacted base keeps it put.
Phoenix summers are when the grid works hardest, which is when people decide they want backup power. The pad is the simple part of that project, but it has to be in the right place, so it comes after the generator and its location are settled.
Why Phoenix homeowners add backup power
Phoenix runs its air conditioning hardest exactly when storms are most likely. The National Weather Service sets the monsoon season at June 15 to September 30, and Phoenix has averaged about 21 days a year at or above 110 degrees since the 1990s. A generator or battery cabinet that sits in the side yard through that season needs a base that stays level through monsoon runoff and summer heat.
The order of work
- Choose the generator or battery system and get its installation manual
- Have the installer set the location to the manual's clearances from windows, doors, vents and lot lines
- Pour the pad to the installer's layout, with conduit or sleeves placed first if they want them
- Let the pad cure before the unit is set
- Licensed electrician and gas fitter make the connections under permit
For other equipment in the same side yard, see AC condenser pads and pool equipment pads.