Home charging setup

I have been charging my electric pickup truck off of an existing standard NEMA 5-15 (120 volt 15 amp) outlet next to our garage for over a year. [And occasionally running a cable out the door from our 240 volt dryer outlet to get a fast charge.]

electrical boxes and meter mounted on a brick wall
Finally this summer I had an electrician run a 50 amp 240 volt circuit out to the side of the garage to put in a “real” charging station. Even though the existing Zivan NG3 240 volt charger will only use 12 amps at 240 volts, the NEMA 14-50 outlet gives me lots of room for improvement (240 volts at 40 amps max continuous draw, or 9.6 kilowatts). It also allows anybody with a super big RV to plug right in!

In addition to the NEMA 14-50 outlet, I also ran a GFCI 5-20 (120 volts at 20 amps) off of the same circuit, in case we want to max out 120 volt charging. The entire circuit runs through a sub-meter that easily allows me to read off how many kWh of electricity the truck uses. So far it’s averaging out to about 7-10% of our total monthly electricity usage. (The small plug at the bottom left of the above picture is the original NEMA 5-15 outlet.)

6 thoughts on “Home charging setup

  1. Looks a little fishy, is that meter there for your incoming house power? or the outlet load? how is that receptacle panel fed? Other than that, awesome!!! really wish I had a 50 amp receptacle on the outside of my house. Then again I wish I had 3 phase 480 VAC coming in but we can always get that. sorry for the grilling. (Electrician in training)

    • The houses’ incoming power meter is elsewhere, near the main circuit breaker panel, and is one of the new radio/electronic ones provided by the utility.

      The 50 amp (6 gauge) wire from the main breaker panel comes through the brick wall behind the check-meter (sub-meter). This meter is simply to measure/display the draw through these outdoor outlets so that I can tell how much power my electric truck is using on a day/week/month basis. I chose the “easy read” digit display instead of mechanical dials to make it easy to read or just take a photo with my phone. Whenever I park the truck I take a photo of the odometer, and whenever I unplug it I take a photo of the meter. Every week or so I enter all the data into a spreadsheet to track total “from the wall” electricity usage vs miles.

  2. Are the 14-50 and 5-20 sockets really on the same circuit? If that’s the case this is not according to code. The 14-50 should be installed on a dedicated 50A circuit. The 5-20 should be on a separate 20A circuit.

    • The 14-50 has a 50A breaker (at the box) plus a 50A breaker on the circuit in the main panel.

      The 5-20 has a 20A breaker (next to the 50A breaker in the box) specifically for it.

      So the circuit is protected at 50A, the 14-50 is redundnatly protected at 50A, and the 5-20 is protected at 20A.

      • There can still be a problem if you are using both the 14-50 and the 5-20 for EV charging at the same time. Let’s say that you draw 32A from the 14-50 and 12A from the 5-20, both well within the 80% limit for continuous load. On the circuit from the main panel to the sub-panel you will have 44A in one of the hot conduits, which is more than 80% of the rated current, however the breaker in the main panel won’t trip since it less than 50A.

        • Fair enough worst case scenario. I’m not worried about it though, as I never use both the 120 and the 240 at the same time, and my current 240 volt charger maxes out around 12 amps….

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