How an electrical panel upgrade is done, step by step

People search for how to upgrade an electrical panel for two reasons: to do it themselves, or to understand what they are paying for. This article is for the second reason. A panel upgrade is licensed work in almost every jurisdiction, and the sequence below is what a properly run job looks like from the owner’s side.

Step one: the load calculation

Before anything is bought, someone calculates what the house draws now and what it will draw with the new loads, such as an EV charger. The calculation follows a method set in the electrical code. It decides whether you need a new panel, a bigger service, a subpanel or simply a load management device. The panel capacity check page explains what goes into it.

Step two: the permit

The electrician applies for a permit with the local building department. Some jurisdictions issue it the same day, others take longer and may ask for a load calculation or a diagram. Work done without a permit can cause trouble with insurance and at resale, as covered in do you need a permit.

Step three: coordinating with the utility

Replacing a panel usually requires the utility to disconnect power at the meter, and a service upgrade requires its approval and sometimes its own work. The disconnect and reconnect are scheduled, and the utility’s calendar often sets the date of the whole job.

Step four: the work day

Power is cut, the old panel is removed, and the new one is mounted. Each circuit is reconnected to a new breaker and labeled. Grounding and bonding are brought up to the current code, which often means new grounding electrode conductors or bonding to water and gas piping. If the service is being upgraded, the meter base and service entrance conductors are replaced at the same time.

Step five: the inspection

An inspector from the building department checks the work before the utility reconnects power, or shortly after under a temporary arrangement, depending on local practice. The inspection looks at the panel, the breakers, the grounding, the labeling and the clearances in front of the panel. Failing items are corrected and reinspected.

Step six: reconnection and checks

Once the inspection is passed, power is restored and each circuit is tested. This is the moment to check that everything in the house works, including appliances with clocks and anything on a dedicated circuit. A good electrician walks through the panel schedule with you and leaves a clear, printed directory on the door.

What the owner can prepare

Clear the space in front of the panel, make a list of what is on each circuit if the old directory is unreliable, and plan for a day without power. Tell the electrician about any future loads you expect, such as a charger, a heat pump or a hot tub, so the new panel has room for them. The overview on electrical panel upgrade covers when an upgrade is worth doing at all.

Keep the permit, the inspection sign off and the invoice together once the job is done. They are what an insurer, a buyer or an incentive program will ask for, and they are much harder to collect after the fact.

How long it really takes

The work day itself is usually one day for a panel replacement, sometimes longer for a service upgrade. The calendar from first call to final reconnection is often several weeks, because the permit, the utility appointment and the inspection each have their own lead times. Asking the electrician for the expected sequence of dates at the start, rather than only the work day, avoids the frustration of a job that seems finished but is still waiting for one of those steps.

Make sure the inspection is recorded as passed, that the panel directory is complete and legible, and that you have the invoice listing the panel model and rating. Test a few outlets on each circuit, check the appliances that were reset, and note anything that does not work while the electrician can still come back easily.