How Long Does an Electrical Panel Upgrade Take?

If you are planning an electrical panel upgrade for your Southeast Wisconsin home, one of the first questions you probably have is: how long will this take? The short answer is that most residential panel upgrades are completed in a single day, typically between 4 and 8 hours of on-site work. But the full timeline from decision to completion involves a few more steps. Here is a detailed breakdown so you know exactly what to expect.

The Typical Installation Timeline

For a standard 200-amp panel upgrade in a typical Southeast Wisconsin home, here is the general timeline:

• Initial assessment and estimate: 1 to 2 days after your call, we visit your home for a free evaluation.
• Permit application: 3 to 10 business days, depending on your municipality. Cities like Waukesha and West Bend typically process permits within a week. Smaller towns may be faster.
• Utility coordination: We Energies needs to disconnect and later reconnect your meter. We schedule this on your behalf, and it usually adds 1 to 3 days to the timeline.
• Installation day: 4 to 8 hours of on-site work.
• Final inspection: Scheduled within a few days of completion. Required by Wisconsin code before the permit is closed.

From start to finish, most homeowners should plan for 2 to 3 weeks total, with the actual hands-on work completed in a single day.

Factors That Affect the Timeline

200-Amp vs. 400-Amp Service

A standard 200-amp upgrade is the most common job and takes 4 to 6 hours. If you are upgrading to 400-amp service — common for larger homes adding EV chargers, workshops, or heated garages — expect 6 to 10 hours. A 400-amp service requires a larger meter base, heavier cabling, and sometimes a second panel, all of which add time.

Age and Condition of Your Home

Older homes in Southeast Wisconsin present unique challenges. If your home was built before 1965, you may have a fuse box instead of a breaker panel, which requires more extensive work to convert. Homes with aluminum wiring (common in the late 1960s and 1970s) may need additional remediation. Knob-and-tube wiring, still found in some pre-war homes in areas like Hartland, Pewaukee, and Cedarburg, cannot be connected to a modern panel without rewiring those circuits first.

Panel Location

If your panel is in an accessible basement location with clear working space, installation is straightforward. Panels located in tight closets, behind finished walls, or in locations that do not meet current NEC clearance requirements (36 inches of clear space in front, 30 inches wide) may need to be relocated. Relocation adds 2 to 4 hours to the job.

Permit Processing Time

Permit timelines vary across Wisconsin municipalities. Waukesha County communities typically process electrical permits within 5 to 7 business days. Washington County is often a bit faster. If your project involves a service entrance upgrade (changing the mast, weatherhead, or meter socket), the permit process may involve an additional review. Your electrician handles this paperwork, but it is worth asking about expected timelines during your initial consultation.

We Energies Coordination

We Energies must disconnect your power at the meter before the panel swap and reconnect it afterward. In most cases, they schedule this within 1 to 2 business days. During peak seasons (summer and early fall, when many homeowners schedule upgrades), it can take slightly longer. Your power will be off for the duration of the installation — typically 4 to 8 hours.

What to Expect on Installation Day

Here is a step-by-step look at what happens during a typical panel upgrade:

1. Power disconnection: We Energies pulls the meter or disconnects service at the transformer.
2. Old panel removal: The existing panel, breakers, and associated wiring connections are carefully removed.
3. New panel installation: The new panel is mounted, and all circuits are reconnected. Each circuit is labeled clearly.
4. Grounding and bonding: Updated to meet current NEC requirements, including proper grounding electrode connections.
5. Testing: Every circuit is tested for proper voltage, polarity, and ground.
6. Power restoration: We Energies reconnects the meter and power is restored.
7. Walkthrough: We walk you through the new panel, explain the circuit directory, and answer any questions.

How to Prepare

You can help the process go smoothly by clearing a 4-foot area around your electrical panel, charging your phones and laptops before the crew arrives, and planning to be without power for most of the day. If you work from home, you may want to arrange an alternative workspace. In winter months, keep in mind that your furnace will also be off during the installation — your home will cool down, so plan accordingly.

Get a Free Panel Upgrade Estimate

At Couillard Electric (WI License #1325885), we have completed hundreds of panel upgrades across Waukesha County, Washington County, and the surrounding areas. We handle the permits, utility coordination, and inspection scheduling so you do not have to. Request your free estimate or call us today.

Ready to Get Started?

Couillard Electric provides free, no-obligation estimates for panel upgrades.