A home EV charger is a piece of electronics on a large circuit, often mounted outdoors or in a garage, and connected to a car that is itself a very expensive piece of electronics. In South Florida it also lives in the part of the country with the most lightning. Surge protection will not make any of that risk disappear, but it is one of the more sensible things to plan when a charger goes in, and in some cases the code already requires it.
This guide covers where surges come from, what a surge-protective device (SPD) does and does not do, the 2020 NEC rule that applies to home services, how protection is layered, and what to do around storms. It is part of our Florida Home EV Charging Guide.
Why this matters more in South Florida
The National Weather Service describes central Florida as the lightning capital of the United States and notes that Florida has the highest number of lightning casualties of all 50 states (NWS Melbourne). NWS Miami adds that lightning is a present, year-round danger in South Florida, particularly in the summer months, and that lightning commonly strikes several miles from the heavy rain of a storm, sometimes 10 miles or more away (NWS Miami lightning awareness). That is the afternoon thunderstorm pattern most of us live with from late spring into fall.
Then there is hurricane season, June 1 through November 30 (National Hurricane Center), when outages, repairs and power being restored add their own disturbances on the lines.
Where surges come from
- Lightning nearby. A strike does not have to hit your house. A strike to the ground, a tree or a utility line nearby can send a surge into the wiring through the service or through other wires entering the house.
- Utility switching. Normal grid operations, and repairs after a storm, can produce short disturbances.
- Inside the house. Large motor loads such as air conditioning compressors and pool pumps cycling on and off create smaller, more frequent transients.
What an SPD does, and what it does not
An SPD limits the voltage that reaches your equipment during a short spike by diverting the excess current to ground. It is designed for brief events. It does not protect against a direct lightning strike to the house or the charger, it does not keep equipment running during an outage, and it is not a substitute for a sound grounding system. A good SPD connected to a poor ground does much less than the label suggests, which is why we look at the grounding electrode and connections as part of the job.
What the code says for homes
Florida is on the Florida Building Code 8th Edition, which uses the 2020 NEC for electrical work (floridabuilding.org). The 2020 NEC added 230.67: all services supplying dwelling units shall be provided with an SPD; it must be an integral part of the service equipment or located immediately adjacent to it (with an exception allowing it at the next level of distribution equipment downstream); it must be a Type 1 or Type 2 SPD; and where service equipment is replaced, all of those requirements apply (code text summary, Leviton).
Why it matters for an EV project: many chargers go in alongside a panel or service upgrade, and replacing the service equipment brings in the SPD requirement. If you are planning an EV charger panel upgrade, surge protection is part of the plan, not an add-on. Your building department confirms how the rule applies to your job.
Layering protection
| Layer | Where | What it helps with |
|---|---|---|
| Service or whole-home SPD (Type 1 or Type 2) | At the meter or main panel | Surges entering from the utility service; protects every circuit, including the charger's |
| Subpanel SPD | At a detached garage or subpanel feeding a pedestal | Long feeders and outbuildings, which see their own surges |
| Point-of-use protection | At sensitive electronics such as the router the charger relies on | Smaller surges and surges on data or cable lines |
For most homes, the first layer does most of the work. A charger on a long run to a detached garage or pedestal may justify a second device at that end. Ask whether other wires entering the house, such as cable and phone lines, share a common grounding point with the electrical service; surges can come in on those too.
What to ask when a charger goes in
- Is there an SPD at the service now? If so, what type is it and is its status indicator still showing it is working?
- If the service or panel is being replaced, how will the 230.67 requirement be met (code text)?
- Is the grounding electrode system in good shape, with tight connections?
- For a detached garage or pedestal, does the far end need its own protection?
- What does the charger manufacturer say about surge protection in its manual?
Around storms
- Before a named storm, charge the car to the level your owner's manual recommends for storage or an outage. Some owners then turn off the charger's breaker until power is stable again, which is a reasonable choice.
- During an outage, do not backfeed the house from a generator without a proper transfer switch or interlock. See generators and EV charging.
- When power comes back, restoration can flicker. Waiting until service is steady before resuming charging is sensible.
- After a lightning event, if the charger will not start, shows a fault, or the SPD's indicator has changed, have it checked rather than repeatedly resetting it. See EV charger not working.
- If water got into the charger or the car, that is a different problem than a surge. See EV chargers in flood zones.
For the bigger storm checklist, see EV hurricane preparation in Florida and our storm readiness page.
Outdoor chargers and long runs
A charger on an exterior wall, a carport or a pedestal is more exposed than one inside a garage, and a long circuit is a longer path for a surge to travel. That does not change the basic approach, but it makes the service-level SPD and good grounding more important, and it is one of the reasons we think about surge protection whenever we plan an outdoor charger or a pedestal.
Questions homeowners ask
Does my EV charger have built-in surge protection?
Check the charger's manual and spec sheet; manufacturers describe their own designs differently. Whatever is inside the charger, protection at the service helps every circuit in the house, including the one feeding the car.
Is a whole-home surge protector required when I install an EV charger?
Not by the charger alone. Under the 2020 NEC rule above, an SPD is required for dwelling services, including when service equipment is replaced, so it comes into play when an EV project includes a new panel or service. Your building department confirms the specifics.
Will a surge protector stop a lightning strike?
No device stops a direct strike. An SPD reduces the damage from the much more common surges that arrive through the wiring from nearby strikes and grid events.
Do surge protectors wear out?
Many SPDs are designed to sacrifice themselves over time as they absorb surges, and many have an indicator light that shows when protection is no longer active. Check it after storm season.
Should I unplug the car during a thunderstorm?
You do not need to go outside in a storm to do it; stay indoors when thunder is heard, as the National Weather Service advises. Follow your charger's manual: some equipment, such as Tesla's Mobile Connector, is not to be used during an electrical storm (Tesla Mobile Connector manual). A service-level SPD helps with the surges nearby strikes send through the wiring. Before a hurricane, see the storm steps above.
Adding a charger, or adding protection?
KRW Electric (license EC13012832) installs whole-home surge protection and EV chargers across Miami-Dade, Broward and Palm Beach, and handles the permit and inspection. Send us a photo of your panel or call (305) 359-7312, and we will tell you what protection you have now and what we would add.
Reviewed by Kyle White, KRW Electric Company LLC — licensed electrical contractor EC13012832.
