Residential · Franklin County & St. Louis, MO
A service upgrade increases the amperage feeding your entire home — the pole, meter, service entrance, and main disconnect. If you're planning an addition, an EV charger, a pool, or a shop, the service upgrade is what makes the rest of it possible. CAS Electric handles 200-amp and 400-amp service upgrades across Franklin County and the Greater St. Louis area — Pacific, Washington, Union, Sullivan, St. Clair, Eureka, Wildwood, Villa Ridge, and Marthasville.
There's a difference between a panel upgrade and a service upgrade, and it matters. A panel upgrade replaces the breaker box on the wall. A service upgrade replaces the incoming service — the mast or lateral from Ameren, the meter socket, the service entrance conductors, and the main disconnect. Most modern jobs do both at the same time.
The most common reason our Franklin County customers request a service upgrade is that they've outgrown 100-amp or 150-amp service. Adding a Level 2 EV charger, a heat pump, or a whole-home generator all bump your calculated load past what a smaller service can safely carry. Rather than get creative with load-sharing devices, upgrading the service gives you real, permanent headroom.
We coordinate everything — the permit, the Ameren disconnect and reconnect, the inspection, and the physical install. In most cases the entire cutover happens in a single day and power is back on the same afternoon.
Service upgrade pricing depends on service size (200A vs 400A), overhead vs underground service, and whether the meter needs to be relocated. We provide a free written estimate after looking at your service — no hourly surprises.
We measure your existing draw, count your circuits, and calculate the service size you actually need — not a guess.
We file the permit with your jurisdiction and lock in the utility disconnect/reconnect window.
Mast or lateral, meter base, service entrance conductors, main disconnect, grounding — most residential upgrades finish in a single day.
Inspector signs off same day when possible, Ameren reconnects, and you're back up before dinner.
A panel upgrade replaces the breaker box on the wall. A service upgrade replaces the incoming service — mast/lateral, meter base, service entrance conductors, and main disconnect. Most jobs today combine both, especially when the panel and service are both original to a 1970s-90s home.
Signs include: frequent main-breaker trips, an electric range plus central A/C and an EV charger all on 100-amp service, plans for a heat pump or addition, or a 60/100-amp service on an older home. We run an actual NEC load calc on-site so you know what you have vs. what you need.
Yes. We schedule the disconnect and reconnect directly with Ameren Missouri as part of the job. You don't need to call the utility yourself.
Often yes, if your yard allows for a service lateral trench and Ameren's local design engineer approves it. It's a bigger job than a like-for-like overhead swap, but many homeowners take advantage of the timing to clean up the exterior.
Not usually. Power is off for the hours it takes to cut the old service and land the new one — typically 4–8 hours. We schedule the reconnect for the same day whenever possible.
Licensed, insured, owner-operated. We respond to all estimates within 1 business day.