AmpereTallyWhether 100 amps is enough, worked out the way an inspector does it.

Will a 200 amp service run a 48 amp EV charger?

Adding a 48 A level 2 EV charger to a 200 amp service
60A of added demand
your existing calculated load has to be under 140 A for this to fit
Adding a 48 A level 2 EV charger to a 200 amp service60 AAdded demand140 AExisting load mus…
Added demand11,520 VA at 125% — a continuous load60A
Existing load must stay under140A
Share of the service this takes30%
Existing service200 A
What is being added11.5 kW, hard-wired, on a 60 A circuita 48 A level 2 EV charger

Notes

  • Do not let anyone guess your existing load, including this page. NEC 220.87 gives the real method: take the highest demand recorded in the last 12 months from the utility, multiply by 1.25, and that is your existing load. Most utilities will supply the figure on request; where there is not a year of history, a recording ammeter left on the service for 30 days does the same job. That measured number, plus the 60 A above, is the answer.
  • 30% of the service goes to this one thing. Whether it fits depends entirely on what the rest of the house already draws. Under 140 A of existing calculated load and it fits; over, and the service has to grow.
  • This is a continuous load, so the code counts it at 125%. A 48 A device is counted as 60 A because it runs for three hours or more without stopping, and conductors and breakers heat differently under a load that never lets up. It is not padding — it is the reason a 40 A charger goes on a 50 A circuit.
  • Load management can save the upgrade, and it is worth pricing first. An EV charger with a load-management device, or an energy-management system that sheds the charger when the range comes on, is a listed and code-recognised way to add a large load to a service that could not otherwise take it. It is frequently a fraction of the cost of a new service.
  • A panel swap and a service upgrade are different jobs. If the panel is full but the service is adequate, a subpanel or a panel with more spaces solves it for far less. If the calculated load exceeds the service, new breakers change nothing — the conductors from the utility, the meter base and the mast all have to grow.

60 amps added, and the honest half of the answer

Adding a 48 amp EV charger puts 60 A onto the service — 30% of a 200 amp panel. Whether it fits depends on what the house already draws, and that is the number every other page on this subject invents.

Measure the existing load instead of guessing it

NEC 220.87 gives the method, and it is easier than the full calculation. Take the highest demand recorded on the service in the last twelve months, multiply by 1.25, and that is your existing load. Most utilities will provide the figure on request. Where there is not a year of history, a recording ammeter on the service for thirty days does the same job.

If that number is under 140 A, this addition fits.

When load management is the cheaper answer

A charger with a listed load-management device, or an energy-management system that sheds it when the range comes on, is a code-recognised way to put a large load on a service that could not otherwise take it. It is often a fraction of the cost of a new service, and it is worth pricing before anyone quotes a mast and a meter base.

A full panel is a different problem

If the breakers have run out but the calculated load is fine, a subpanel or a panel with more spaces solves it cheaply. Only when the load exceeds the service does the utility conductor, meter base and mast all have to grow.

Nearby sizes

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