A standby generator is only as good as its sizing. Too small and it cannot carry your essentials; too large and you have overspent on capacity and fuel. The right size comes from your actual loads — not a round number off a shelf.
Whole-home vs essential circuits
You have two strategies. Whole-home backup powers everything automatically — simplest to live with, larger generator. Essential-circuit backup uses a smaller unit and a transfer switch that covers the loads you choose: heat, fridge, well pump, sump, key outlets and lighting. Many homeowners are perfectly happy with a well-chosen essential setup at a lower cost.
How sizing actually works
A licensed electrician adds up the running watts of the loads you want to back up, then accounts for the starting surge of motors like your AC, well pump and refrigerator, which briefly draw far more than their running figure. That surge, not the steady load, often determines the generator size.
What drives generator size
- Starting surge of motors (AC, well pump, fridge) — usually the deciding factor.
- Whether you want whole-home or essential-circuit coverage.
- Electric vs gas heat and water heating.
- Fuel source available: natural gas or propane.
Size to the surge, not just the steady load — that is what keeps the generator from stalling when the AC kicks on.
The automatic transfer switch
The piece that makes a standby generator effortless is the automatic transfer switch. It senses an outage, safely disconnects you from the grid, and starts the generator within seconds — then switches back when utility power returns. Proper installation and a correctly sized transfer switch are what separate a reliable system from a frustrating one, which is why this is licensed-electrician work end to end.
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Whether it is a quick repair or a full upgrade, we will scope it and quote it in writing.