Panel Upgrades & Rewiring
200-amp service upgrades, fuse box replacement and whole-home rewiring, permitted and inspected.
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Residential service
Whole-Home Standby Generator Installation
Missouri storm season takes the grid down every year, and a house without backup power loses the sump pump, the furnace and the freezer along with the lights. APEX Electric installs automatic standby generators and transfer switches so the changeover happens in seconds, whether anyone is home or not.
Whole-home or critical circuits
A whole-home system carries everything, including central air. A critical-circuit setup backs up a defined list — sump pump, furnace, refrigerator, a few outlets and lights — for a fraction of the cost and fuel.
Which one is right depends on how you actually use the house. We size the system from a real load calculation rather than selling you the largest unit on the shelf.
Transfer switches done properly
The transfer switch is the safety-critical piece. It isolates your home from the utility so backfeed cannot injure a lineworker restoring the grid. Backfeeding through a dryer outlet with a 'suicide cord' is illegal, and it kills people.
We install listed automatic transfer switches wired to code, with the generator exercising itself weekly so you find out about a problem on a Tuesday afternoon instead of during a storm.
Fuel, siting and permits
Natural gas means no refueling and no storage tank. Propane suits homes outside a gas main. Either way the unit has to sit a code-required distance from windows, doors and the meter, on a pad that will not settle.
We coordinate the gas connection, the pad, the electrical permit and the inspection, and register the warranty on your behalf.
What this covers
- Whole-home automatic standby systems
- Automatic & manual transfer switches
- Critical-circuit backup panels
- Natural gas & propane
- Portable generator inlets
- Load calculation & sizing
Available across O'Fallon, St. Charles, St. Peters, Wentzville and the rest of St. Charles County.
(660) 342-5886QuestionsStandby Generators
Standby Generators
questions.
The things people ask us most about this work.
It depends on whether you want whole-home coverage or a critical-circuit backup, and on your largest motor loads — usually the air conditioner and the well pump. We run a load calculation before recommending a size.
An automatic system typically starts and transfers within about ten seconds of losing utility power, with no action from you.
Yes. A power inlet box with an interlock kit is a much cheaper way to safely feed a portable generator into the panel. It is manual rather than automatic, but it is safe and code-compliant.
Annually, plus an oil change on the manufacturer's schedule. The weekly self-exercise cycle handles routine readiness; the annual service catches wear before it matters.
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Learn moreNeed standby generators?
Tell us what you are working with. We will give you a fixed price and a date, at no charge.
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Get a quote for standby generators
Send the details and we will come back the same business day.
Call us(660) 342-5886
- Office
- 105 Hawks Haven Dr.O'Fallon, MO 63368By appointment — we come to you for estimates.
- Hours
- Monday – Friday7:00 AM – 6:00 PMSaturdayBy appointmentEmergency service24 / 7
- Emergencies
- Burning smell, sparking, a dead service or water near electrical equipment — call the main number any hour.
- Service area
- O'Fallon · St. Charles · St. Peters · Wentzville · Lake Saint Louis · Cottleville · Dardenne Prairie · Chesterfield
Get in touch
Call or email us
The fastest way to get an estimate is a phone call. Tell us what is going on and we will tell you what it needs, what it costs and when we can be there.
Helpful to include
- What is happening, and roughly when it started
- Home or business, and the town
- A photo of the panel or the problem
- When you are usually available
Monday – Friday: 7:00 AM – 6:00 PM. Emergency service available 24/7 — call the main number any hour.
Would rather just talk to someone? Call (660) 342-5886 — for anything urgent that is the fastest route.