Panel Upgrades for EV Chargers in South Florida

Florida Home EV Charging Guide

Upgrade, load management or neither: how to tell

The short answer: most homes need a load calculation, not automatically a new panel

When a homeowner calls about an EV charger, the first worry is usually the panel. Some homes do need a panel or service upgrade before a Level 2 charger can go in. Many do not. The difference comes down to two separate questions, and it helps to keep them apart from the start.

• Does the panel have physical room? A Level 2 charger needs a two-pole breaker, which takes two spaces in most residential panels. A full panel can sometimes be fixed with a small subpanel or by rearranging circuits, without touching the service.
• Does the service have capacity? This is the real question. The service rating (100, 125, 150 or 200 amps on most South Florida homes) is the total the house can draw from the utility. An EV charger is a large load that can run for hours, and the existing loads have to leave room for it.

A panel with empty spaces can still be out of capacity, and a crowded panel can have plenty of capacity. That is why we start with a load calculation instead of a look at the breakers. If you want the homeowner's version of that check, our guide does my panel have room for an EV charger? walks through what you can see on your own panel label.

Why South Florida homes run out of capacity

The homes we work in across Miami-Dade, Broward and Palm Beach have a particular load profile. Central air conditioning runs most of the year and is the single largest load in most houses. Many homes also have an electric water heater, an electric range, an electric dryer and a pool pump, and some have heat strips in the air handler for the few cool nights. Gas service is less common here than in many parts of the country, so a lot of houses are all-electric.

Add the housing stock to that. Much of the area was built between the 1950s and the 1980s, and many of those homes still have the 100 amp service they were built with, sometimes with a panel that has been added to several times. A 100 amp service in an all-electric house with a pool can already be close to its limit before a car is involved. The same service in a smaller house with gas cooking and gas water heating may have room to spare. The panel label does not tell you which one you have. The loads do.

For older homes there is a second layer: the condition of the equipment itself. Fuse panels, some brands of breaker panels with a poor track record, aluminum branch wiring and corroded meter cans all change the plan. We cover those in EV charging in older Florida homes.

How the load calculation works

Florida is on the Florida Building Code 8th Edition (2023), and its electrical volume is the 2020 National Electrical Code (NEC 2020, see floridabuilding.org). That code gives electricians two ways to check whether an existing house can take a new load.

1. The existing-dwelling calculation. The house's loads are listed from the square footage and the nameplates of the fixed appliances, and the code's demand factors are applied: for an existing dwelling, the first 8,000 VA counts at 100 percent and the remainder at 40 percent, with heating and air conditioning handled under the method's own rules. EC&M summarizes the method here. The result is compared with the service rating.
2. Measured demand. Where a full year of maximum-demand data for the service is available, the code allows the existing load to be taken from that data, with a 125 percent factor, plus the new load (UpCodes, determining existing loads). Ask your utility whether that data exists for your account; it is not available for every home.

The EV charger enters the calculation at its rating. Because EV charging is treated as a continuous load, the breaker must be at least 125 percent of the charger's maximum output: a 40 amp charger needs a 50 amp breaker, a 48 amp charger a 60 amp breaker (Mike Holt, NEC Article 625 summary). The table below shows the common sizes.

*Scaled from the Alternative Fuels Data Center estimate of about 25 miles of range per hour for a typical 7.2 kW Level 2 charger. Your car's efficiency, and whether it can accept the full rate, change the real number. The point of the table is that you have choices. A 32 amp charger adds a full day's driving overnight for most people, and it asks noticeably less of the service than a 48 amp one.

When an EV charger actually needs a panel or service upgrade

After the calculation, most homes fall into one of four outcomes.

A few situations push a home toward the last row regardless of the arithmetic: a fuse panel, a panel whose manufacturer no longer makes replacement breakers, visible corrosion or heat damage at the meter or main, service conductors in poor condition, or a household that is also planning a second EV, an addition, a pool heater or a kitchen remodel. If several of those are coming, one upgrade now is usually better than a load manager now and an upgrade in two years.

Load management is the other real option, and for many 100 and 125 amp homes it is the right one. We compare the two directly in EV load management vs a panel upgrade, and we walk through worked examples on a 100 amp house in can you install an EV charger on a 100 amp panel?

What an EV-driven service upgrade involves

A panel swap on the same service size stays inside the house's own equipment. A larger service is different, because the utility's side of the meter has to support it. With FPL, which serves most of South Florida, a service upgrade starts with a project application, and FPL reviews the request to decide whether its own equipment needs to be upgraded, replaced or added. Some projects only need a disconnect and reconnect while the electrician works; FPL notes that upgrading its equipment requires a power outage while the new equipment is installed (FPL Project Portal, project types). The governing building department inspects the panel before the home is reconnected (FPL Project Portal, how it works).

Homestead and Lake Worth Beach run their own utilities (City of Homestead, HPS Energy; Lake Worth Beach Electric Utilities), so homes there follow those utilities' processes instead.

On a newer service, the 2020 NEC also requires one- and two-family homes to have an emergency disconnect at a readily accessible outdoor location (IAEI Magazine, residential changes for the 2020 NEC), which affects where the new equipment goes. Our post when an EV needs a bigger electric service covers the sequence step by step.

What KRW Electric handles

KRW Electric Company LLC, licensed electrical contractor EC13012832, installs home EV chargers and does panel and service upgrades across Miami-Dade, Broward and Palm Beach. On an EV project we:

1. Look at the existing panel, service and meter, and list the large loads in the house.
2. Run the load calculation and tell you which of the four outcomes above applies, and why.
3. Size the charger circuit to the charger you have chosen, or help you choose a setting that fits.
4. Pull the permit and schedule the inspection with your city or county building department.
5. On a service upgrade, explain what the utility's side involves and plan the work around the disconnect and reconnect.
6. Install the charger or receptacle, test it, and walk you through the settings.

The charger installation itself is described on our EV charger installation page, and general panel replacement and upgrade work, whether or not a car is involved, is on our panel upgrade page. The full set of homeowner guides lives in the Florida Home EV Charging Guide.

What to have ready before you call

• A photo of the panel with the door open, and a close photo of the label inside the door.
• A photo of the main breaker, which shows the service size (100, 125, 150 or 200).
• A photo of the meter and the area around it, outside.
• A list of the big loads: A/C tonnage if you know it, electric or gas water heater, range and dryer, pool pump or pool heater, any hot tub.
• The charger you plan to buy, or the car, and where you park.
• Whether a second EV, an addition or a remodel is likely in the next few years.

With those, we can usually tell you on the first visit whether you are looking at a straightforward circuit, a load management device or a service upgrade. Send them through our contact page or call (305) 359-7312.