EV charging station design
and engineering.

What does an EV charging site assessment look at?

The service, the distance and the lot, in that order.

The assessment starts at the electrical service: what is there now and the size of the transformer on your property. Then the distance from that service to the stalls you want, because that run sets the trenching and it is usually the largest variable between two sites that look identical from the street. Then the lot itself, which means the traffic pattern, turning radius, accessible stalls, and where a charger can sit without becoming a target for a delivery truck.

Everything the design says later is decided by what gets measured on that walk.

How do I know whether my site can support DCFC?

A load calculation answers it, and the transformer usually decides it.

DCFC arrives as a block of load most retail services were never sized for, so the question is rarely the panel and almost always the service and the transformer feeding it. Three things settle it: the capacity left after the store, what the transformer on your property can carry, and how far the stalls sit from the service.

Two sites that look the same from the road can land in very different places once those three are measured, which is why we assess before we quote.

The full project timeline

How much power does DCFC need?

Three-phase service, usually at 480 volts on commercial sites.

A DC fast charger takes three-phase power and is normally fed at 480 volts. The actual draw depends on the charger you choose and how many you install.

That is why we ask for the make and model early. The manufacturer’s rated input is what the load calculation and the utility application are built from, so give us the equipment and we will tell you the service it needs.

How long does the utility take, and what drives it?

Longer than the rest of the project, and the transformer drives it.

The utility studies the added load on the existing transformer, based on the number of chargers you want to add. What moves the date is equipment lead time, the utility’s own engineering review, and whether the upgrade needs work in the right of way.

It varies by market and sits outside anyone’s control, which is exactly why the application goes in at the start of design rather than at the end of it.

What drawings does a permit office need for EV charging?

A site plan, an electrical single line and construction details, at minimum.

Most jurisdictions want a site plan showing stall layout, charger locations, the conduit route and accessible parking; a single-line diagram from the service through to the chargers, with the load calculation behind it; and details for the pads, bollards and mounting. Some add a photometric plan or a separate accessibility exhibit.

The list belongs to your local authority having jurisdiction, so we confirm it with them before the set is drawn rather than after it comes back. Check local and state requirements.

See permitting

What is NEC Article 625, and what does it require?

The section of the National Electrical Code written for EV charging equipment.

Article 625 covers the conductors and equipment that connect a vehicle to the supply, and it is where the rules for charging equipment, disconnects, cord and cable management, and overcurrent protection live. The requirement that shapes a design most is continuous load: charging circuits are sized at 125 percent of maximum draw.

Which edition applies to you depends on what your state and city have adopted, and adoption lags publication, so we design to the version enforced at your address rather than the newest one in print. Check local and state requirements.

Do EV charging drawings need a licensed engineer’s stamp?

For commercial work at this scale, in most jurisdictions yes.

Commercial electrical work that touches the service usually has to be sealed by an engineer licensed in the state where the site sits. Some smaller projects get through on a contractor-drawn set.

Because it varies, we confirm the requirement with the permit office and the utility before the set is drawn, and we produce stamped drawings where they are required. Check local and state requirements.