Only a 100 amp service
Plenty of older Tri-Cities homes still have 100 amp service. Adding a 48 amp continuous load to that usually calls for either load management or a service upgrade.
A Level 2 charger is a 240 volt circuit, a load calculation, a permit and an inspection. The load calculation is the part that decides everything else, because it tells us whether your existing service can carry the charger or whether the panel has to be dealt with first. Kyle Gale runs that calculation before quoting, so the number you get is the real one.
Plenty of older Tri-Cities homes still have 100 amp service. Adding a 48 amp continuous load to that usually calls for either load management or a service upgrade.
A 240 volt circuit needs two adjacent spaces. A full panel means a sub-panel, a panel replacement, or a listed tandem arrangement if the panel is rated for it.
Level 1 charging on a 120 volt receptacle adds only a few miles of range per hour. For most Tri-Cities commutes that barely keeps even overnight.
A Level 2 charger is a 240 volt circuit, a load calculation, a permit and an inspection. The load calculation is the part that decides everything else, because it tells us whether your existing service can carry the charger or whether the panel has to be dealt with first. Kyle Gale runs that calculation before quoting, so the number you get is the real one.
Before anything can be sized, we have to know what your service can carry. NEC 220.83 gives a calculation method for adding load to an existing dwelling. NEC 220.87 gives a second method based on measured maximum demand, using the highest fifteen-minute demand recorded over the previous year multiplied by 125 percent. Where good utility interval data is available, 220.87 frequently shows more available capacity than the calculated method does.
This matters because the answer changes the price of the job by thousands of dollars. A 200 amp service in a newer West Richland or south Kennewick house often has room for a 60 amp circuit without touching the panel. A 1950s Richland house on 100 amp service with an electric range and dryer may not, and then the conversation turns to a service upgrade or a load management device. We run the numbers before quoting, not after the work has started.
EV charging is a continuous load, so the circuit gets sized at 125 percent of the charger output under NEC 625.41. That is why a 40 amp breaker supports 32 amps of charging, a 50 amp breaker supports 40 amps, and a 60 amp breaker supports 48 amps. Charger amperage is what determines charging speed. Most Level 2 units are adjustable, so a 48 amp unit can be commissioned at 32 amps on a 40 amp circuit when that is what the service supports.
Faster is not automatically better. A 32 amp charger adds roughly 25 to 30 miles of range per hour for a typical EV, which fully recovers a normal Tri-Cities commute in a couple of hours overnight. The case for 48 amps is a large battery, a long daily drive, or two vehicles sharing one unit. Paying for a service upgrade to reach 48 amps when 32 already covers your driving is money that could have stayed in your pocket.
A NEMA 14-50 receptacle lets you plug in a portable charging cord, which is convenient and makes the unit easy to take with you or replace later. It comes with rules. The receptacle circuit requires GFCI protection under current code, the receptacle itself should be an industrial-grade device rather than the cheapest one on the shelf, and the circuit tops out at 40 amps of charging on a 50 amp breaker. Cheap 14-50 receptacles overheating under continuous load is a documented problem.
Hardwiring removes the receptacle as a failure point, and it is required above 48 amps. It also mounts more cleanly outdoors and generally holds up better through years of daily plugging and unplugging. The tradeoff is that swapping the unit later becomes an electrician visit instead of unplugging a cord. For a permanent home charger in a garage or on an exterior wall, we usually recommend hardwired unless you have a specific reason to want the plug.
Pasco is the fastest-growing city in the Tri-Cities and it shows in the wiring. The west side along Road 68 and out into Broadmoor is largely new construction, subdivisions that went up quickly with production wiring and minimum circuit counts. Those homes rarely need a service upgrade. What they need is more of everything the builder skipped: garage circuits, patio outlets, EV chargers, ceiling fans in bedrooms that only got a ceiling box, and lighting in rooms finished with a single fixture. Fast growth also means a lot of first-time homeowners who have never had to think about a panel before.
Free estimates across the Tri-Cities. Call Kyle and the crew, or send the details and we will come look.