Planning for an EV charger at the panel and in the garage

Planning workflow

1. Mark the panel location and record how many spaces remain, since a double-pole circuit needs two adjacent spaces.
2. Locate where each vehicle actually parks, and which side its charge port sits on.
3. Draw the conduit route from the panel to that position, noting every wall, ceiling, and slab crossing.
4. Choose a mounting height and position clear of door swings, vehicle travel, and stored items.
5. Record the reservation on the plan so a later electrician inherits the intent rather than guessing.

Formula or decision logic

Charging speed depends on delivered power, and power equals volts times amps. A 240 V circuit at 40 A delivers 9.6 kW at the outlet, while a 120 V, 12 A connection delivers about 1.44 kW - roughly six to seven times slower for the same energy. Whether that circuit can be added is a service-capacity question answered by a load calculation, not by counting free breaker spaces. Even where capacity exists, the run length affects conductor sizing, so a route drawn now is worth more than a breaker reserved now. Every ampacity, conductor, disconnect, and GFCI decision comes from the locally adopted electrical code.

Worked planning example

A panel sits on the far side of the house from the garage, 62 ft of routed distance away. Reserving a 3/4 in conduit along the ceiling of an unfinished basement to a garage stub costs a few hours during construction. Doing the same work later means either surface conduit across finished space or opening ceilings. The plan records the route, the two reserved panel spaces, and a mounting position 4 ft above the garage floor near the front-left corner of the parking bay, matching the charge port on the intended vehicle.

Limitations and review boundary

• Circuit sizing, conductor selection, disconnects, and protection are determined by a qualified electrician under the adopted code.
• Existing service capacity may require a load calculation, a load-management device, or a service upgrade.
• Charging equipment, connectors, and vehicle capability change; a reserved route is more durable than a reserved product choice.

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