I’ve never used this outlet in my garage, but I’ll be using it a lot very soon. It is rated for 20 amps at 240 volts and is called a NEMA 6-20. The outlet was pretty old, so I replaced it with a new one, which cost less than $6, including the face plate.
What will I be using this for? To charge my Tesla Model 3! The Model 3 can plug into a standard home outlet in the United States, which is a NEMA 5-15 (120 volt / 15 amp). The charge speed is really slow though, only getting 3 miles of range per hour. A NEMA 6-20 can produce 15 miles of range per hour. To put that in perspective, if the car was down to 10% battery it would get back up to 90% in about 16.5 hours.
When I replaced the outlet I noticed that the wiring was only 14 AWG, which is good for 15 amps at 240 volts. It should be using 12 AWG for 20 amps, so we’ll see what kind of charging speed I get when I have the car. If it’s only able to pull 15 amps, then the charge rate would drop to 11 miles of range per hour. Even that should be plenty of juice for my driving habits, but I’ll have to see.
I could always reroute an existing 30 amp circuit that isn’t used and install a NEMA 10-30 (240 volt / 30 amp) outlet, which gets 22 miles of range per hour. Or go big by installing a 50 amp breaker and a NEMA 14-50 (240 volt / 50 amp) outlet, which charges at 30 miles of range per hour and could provide a full charge overnight. If I’m really in a bind I can always drive over to the Meijer in Bay City which has Tesla Superchargers.