Ah, OK. Preparing for future upgrading is a good use case. But the thing that matters for that is not having to redo the wiring run. That can be painful and expensive to tear out and redo later. So the right thing to do for that is to go ahead and use oversized wire now. You can still have the ends with the breaker and outlet be easily changeable later. So that could be done as a 20 or 30A circuit now, and switched in a few minutes to something bigger if the opportunity comes later to upgrade.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
NEMA14-50 question
- Thread starter relaxjim
- Start date
If you do go for a 14-50R outlet despite your electrical system's 20A capacity, a way to be safer is to plug in a 14-50P to 6-20R adapter into the 14-50R outlet, then use the 6-20P adapter with the Tesla mobile connector to ensure that no more than 16A charging is used, no matter what the car is set at.
pikeman
Member
Does “off-grid” include ignoring the national electrical code?
I was all set to install a 14-50 receptacle. Then I ran into the recent update to the code that requires gfci on all circuits. Then I read on this forum that the GFCI in the car and the other in the circuit breaker don’t always play nicely and then the car doesn’t get charged, but that the Tesla wall charger negotiates this obstacle. That put me back to the beginning. I found a licensed electrician who had inventory of the Tesla chargers, got a permit, did the work, and the inspector was satisfied. Yes, it was more expensive, and I missed the satisfaction of doing the work. All my supplies were returned.
So hasn’t the National Electric Code rendered the 14-50 for our cars, as obsolete? Supposedly you can buy second hand non-gfci circuit breakers, but I’m not doing that.
So hasn’t this double gfci issue made the 14-50 unfeasible?
I was all set to install a 14-50 receptacle. Then I ran into the recent update to the code that requires gfci on all circuits. Then I read on this forum that the GFCI in the car and the other in the circuit breaker don’t always play nicely and then the car doesn’t get charged, but that the Tesla wall charger negotiates this obstacle. That put me back to the beginning. I found a licensed electrician who had inventory of the Tesla chargers, got a permit, did the work, and the inspector was satisfied. Yes, it was more expensive, and I missed the satisfaction of doing the work. All my supplies were returned.
So hasn’t the National Electric Code rendered the 14-50 for our cars, as obsolete? Supposedly you can buy second hand non-gfci circuit breakers, but I’m not doing that.
So hasn’t this double gfci issue made the 14-50 unfeasible?
davewill
Active Member
It's not the two GFCIs, but the ground check at startup that Tesla builds into their mobile connector...and it generally does not cause any problems. I think that either solution is acceptable. The problem here is not anything to do with GFCI, but hving a 50a circuit that you can't draw 50a from.
In this case, at least, it doesn't sound like overdrawing the circuit will be a safety issue in terms of overloading conductors as much as it might cause his off-grid inverter to shut down. I also suspect he could end up setting his charge current quite a bit lower than 20a anyway, so he might well find himself having to check the car's setting all the time even if he were to go with the 6-20.
The real answer in this situation would be an EVSE that was aware of his solar output, house and car battery levels, and other loads in the house, and automatically adjusted his charging rate.
circuit installed( GFCIs etc) very happy to report I'm getting 21 miles of range per hour of charge at 20 amps. This is better than I had hoped for. If it gets cloudy I just drop the amps accordingly. Because of the intense sun here in Hawaii my home batteries are full as of 9:30am so I can start charging then. Rule # 1 ALWAYS set the charge rate in the car as it automatically defaults to 32amps. Someday I will upgrade my solar system, but this 12 year old system is performing beautifully
I'm a Tesla owner and live off-grid also. My total solar capacity is about 6KWs and I have 300Ah at 48v of battery storage. I installed a 14-50 240v outlet with a 30A breaker in the panel. I use the outlet for other things also. I limit my car charge to 10A during the day. I don't charge at night. I don't commute so the car may sit for 3 days before I need it. This system has been working great for me so far.
Similar threads
- Question
