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400 Amp Electrical Service
Breaker brands matter here, because some are no longer made and some were never good. Most panel calls start as something smaller: a breaker that will not reset, a burning smell, an inspector’s note on a sale.
400 Amp Electrical Service in O’Fallon and across St. Charles, St. Louis, Lincoln and Warren counties.
Owner-operated: the person who answers the phone is the person who measures it.
5.0 from 94 Google reviews · BBB A+ since 2022
What this work actually involves
The load gets calculated against what the house actually runs, not against a rule of thumb. If the existing service carries it, you hear that.
Clint measures before he quotes. The reading comes first, then what it means, then the one repair that solves it. If the honest answer is smaller than what you called about, that is the answer you get, even when the bigger job pays better.
Work that needs a permit gets one, and work that needs an inspection is left ready for it. One person does the diagnosis and the repair, so nothing is lost between a salesman and a technician.
When people call about this
- No room left for a new circuit
- Fuses instead of breakers
- Lights that dim when a large appliance starts
- Breakers that trip under normal load
Why people choose Clint for it
A one-person shop cannot be in two places at once, so you get a real date instead of a window. What you also get is the same person every time.
Seventeen years in the trade, four of them on his own, 5.0 from 94 Google reviews and an A+ BBB accreditation since 2022.
Where this is done
A roughly fifty mile working radius from O’Fallon, covering thirty municipalities across five jurisdictions in the St. Louis metro.
See the full service area, or the rest of our panels & service work.
Sub-panel, service upgrade, or neither
These three get confused constantly and they differ by thousands of dollars. A sub-panel adds places to land circuits and is right when the service carries the load but the box is full. A service upgrade raises what the house can draw and is right when the calculation says the service is genuinely at its limit.
Neither is right when the real problem is one overloaded circuit, which is more common than either. The load calculation is what separates the three, and it happens before anything is quoted.
Why the bus matters more than the breakers
Breakers are replaceable parts. The bus bar they clip onto is not: it is the panel. Heat damage there shows as discolouration, pitting, or a breaker that will not sit tight, and none of those improve on their own.
That is why a panel assessment means taking the cover off rather than reading the label on the door. A panel with a sound bus and a tired breaker is a cheap repair. A panel with a damaged bus is a replacement, and you are told which you have with the reason attached.
When 400 amp service is genuinely the answer
Four hundred amp service is right for large houses with electric heat, multiple chargers, a shop, or an accessory dwelling on the same meter. For most homes it is more than the load calculation supports.
The calculation decides it, and you see the number. Where it is justified it usually arrives as two 200 amp panels off a single meter, which is also easier to feed and to label.
Why the diagnosis comes before the quote
A symptom has several possible causes with very different prices, and the only thing that separates them is a measurement. Quoting the expensive one covers the risk; quoting the cheap one and finding the expensive one mid-job is worse.
So the reading happens first, you are told what it says, and then the work is scoped to it. Where the honest answer is the small repair, that is the answer you get, even when the larger job pays better.
Permits, inspections and why they vary here
Requirements genuinely differ across this metro. O’Fallon, St. Charles, St. Peters, the St. Louis County municipalities and St. Louis City each run their own process, and what one treats as a minor repair another permits and inspects.
Work that needs a permit gets one, and work that needs an inspection is left ready for it with the panel labeled and the junctions accessible. That matters most before a closing, when an inspector’s written item becomes someone’s negotiating position.
“Infinity came out for same day service after an electric line had been cut in my yard. He was able to locate and correct it very quickly, eliminating any risk of injury or additional power outage.”
Melissa Johnson · Google review
How the visit goes
- The call
You describe what the house is doing and what prompted it: a tripping breaker, an inspector’s note, a planned addition. That shapes what gets measured first.
- The measurement
Load across the service under real conditions, voltage at the main, the condition of every lug and the bus. On an older panel, the breaker brand gets identified, because some have no listed replacement still made.
- The finding
You get the number and what it means. If the service carries what the house asks of it, you hear that, and the conversation becomes a sub-panel or a single circuit instead of a service upgrade.
- The work
Permit where required, utility coordinated for the disconnect, new equipment installed, every circuit identified and labeled, and the site left ready for the inspector.
What the job includes
- A load calculation against what the house actually runs, given to you as a number
- Permit application where the municipality requires one
- New panel, breakers and a legible circuit directory
- Utility coordination for the disconnect and reconnect
- Grounding and bonding brought to current requirements
- The site left ready for inspection, and the inspection attended
What it does not
- Drywall repair beyond the panel opening
- Appliance repair, which is a different trade
- Work on the utility side of the meter, which is the utility’s own
Plumbing, HVAC and structural work get a pointer to someone who does them properly. See the work itself, or send the details.
Related panels & service work
400 Amp Electrical Service across the metro
Where the house is changes what the work involves. Clint works out of O’Fallon across five jurisdictions, and the same service means different work in each.
St. Charles County
Out here the panels are not old, they are full. Houses built through the 1990s and 2000s got services sized for the loads of their decade, and the loads have since changed.
St. Louis County
This is where the genuinely old wiring lives: cloth insulation, no equipment ground, fuse panels and the mid-seventies aluminum. Each has an accepted remedy rather than requiring a whole-house rewire.
St. Louis City
Much of this stock is two and four family, which means shared services and panels that are rarely labeled accurately.
Every municipality covered is listed on the service areas page.
Questions worth asking first.
Do I need a bigger service, or just more space in the panel?
Those are different problems. A full panel with spare capacity takes a sub-panel or tandem breakers. A panel that is out of capacity takes a service upgrade, and the load calculation tells us which one you have before anything is ordered.
Will the power be off all day?
A panel change means the service is off while the work happens, usually most of a working day. You will be told the window before the day starts, and the utility and inspection timing are arranged around it.
How do I know if my panel brand is a problem?
Federal Pacific Stab-Lok and Zinsco both have documented failure-to-trip histories and no current listed replacement breaker, so the panel gets replaced rather than repaired. The label on the door identifies it in seconds.
How long have you been doing this?
Clint has seventeen years in the trade and has been running his own shop out of O’Fallon since 2022.
What do your reviews say?
5.0 from 94 Google reviews, and A+ accreditation with the BBB held since 2022. The reviews are on the reviews page with links to where each was posted.
Talk to the person who will do the work.
No dispatcher, no salesman. Clint takes the call and Clint does the job. 400 Amp Electrical Service in O’Fallon and across the metro.
Mon-Thu 8-5 · Fri 8-4 · Sat 10-3. A written note works too.