Market guide
Loads, starts and fuel
Running demand, motor starts and the installed fuel decide useful generator sizeA square-foot rule cannot size a standby system. The working load schedule names essential circuits, simultaneous demand, motor starts, acceptable shedding and the output available on the fuel the site will actually use.
01
Loads
Separate essential, managed and excluded circuits
Refrigeration, pumps, heat controls, medical necessities and communications deserve explicit priority. Resistance heat and vehicle charging can dominate a plan.
- Measure
- Use equipment nameplates and qualified load data.
- Sequence
- State which large loads may run together.
02
Starts
Motors need brief power above running demand
Air conditioners, well pumps, sump pumps and compressors can overload an otherwise adequate generator during startup.
- Data
- Collect locked-rotor or tested starting information.
- Manage
- Use approved staging or soft-start equipment when designed.
03
Fuel
Size from natural gas or propane output
Many models produce less power on natural gas than on LP. Full-load consumption must remain available during a utility outage and cold or hot weather.
- Pipe
- Have the meter, regulator and route calculated for full demand.
- Tank
- Model propane autonomy and refill access during a regional event.
Evidence used
First-party sources behind this guide
- 01Current home standby generatorsGenerac · checked August 15, 2026Open source
- 02Current home generatorsKOHLER Home Energy · checked August 15, 2026Open source
- 03Generator buying guideConsumer Reports · checked August 15, 2026Open source