It sounds like there are a ton of really knowledgeable folks on this thread. I am not one of those and I'm also trying to determine what is the best option of setting up my home charging. I've read a lot of the comparison's between getting the Tesla Wall Connector vs a nema 14-50r outlet. It seems that spending $500 + an electrician to come out and set it all up seems pretty expensive for just a few more miles/hr of charge. I get that the Tesla wall charger protects against the elements, which I will need as my car will be parked under a carport. However, wouldn't purchasing a Nema 14-50 or 6/50R power outlet provide the same protection against the elements at a drastically cheaper cost? Sorry if I sound ignorant to all this electrical stuff but I am. LOL
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Best practice for installing home charging?
- Thread starter KieranTS925
- Start date
jrweiss98020
Tessa's Tesla
It will cost the same to run the electric service (240V / 50 or 60A) to the carport. The 14-50 outlet will be much cheaper than the TWC, and will get you 32A of charge current vs the 40 or 48A with the TWC. An advantage of the 14-50 is that you can use it for other things (welder, compressor...) if needed. You can also plug in an aftermarket charger like the ChargePoint Home Flex that will get you 40A of charge current and possibly a rebate from your utility or municipality. After rebates, my Home Flex cost me about $20.
davewill
Active Member
Not necessarily. A 14-50 plug will probably cost more to install because it requires a GFI breaker (expensive) in most juridictions. Also, a quality 14-50 plug is not cheap. There are some in the $10-20 range, but they've been shown here to be problematic time and again, so expect to pay $70+ for a good one (see Master Thread: Definitive 14-50 NEMA Outlet Guide). The upshot is that it might cost you an extra $350-450 in parts to do the install for the 14-50. With the recent price drops on the Tesla wall connector, the final total may end up much the same.
Not only is the wall connector better buiilt, but you have the mobile connector to keep in the car, or use as a backup. Also, if being installed in a carport, the wall connector also has the advantage of being better suited to being out in the elements.
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2 days between order confirmation and shipping info for me.
For an outlet (versus a hardwire setup), you could need a GFCI breaker (+$100) and the outlet (+$50 for a good one), so an extra $150 in parts for the outlet. Add $45 for the plug adapter to get $195. So the wall connector at $495 would be $300 more expensive. Or more, if wiring for 60A costs more than for 40A/50A.
jrweiss98020
Tessa's Tesla
You live in the state of Washington. Yes it was required. That requirement was put in place in the 2017 version. Washington is on version 2020 already. We see lots of electricians miss this requirement.
Although it's a requirement, the mobile charger has its own GFCI and they're said to cause trips between each other.
Is there a recommended solution for this? Does the GFCI requirement render all mobile connectors permanently problematic?
DeltaOne
Member
I've been charging my Model 3 for the last twelve months without problems. Cable runs from my electrical panel to a box with a GFCI, then on to a box that houses a NEMA 14-50 outlet.
It's worked flawlessly. No tripped breakers in twelve months.
It does. But that can only protect farther down the line, at the plug end that goes into the car. If you are standing in a puddle of water and are attempting to plug it into the wall, and your finger slips and touches the prongs, there's a shock risk there that GFCI in the circuit could help, but the GFCI in the charging cable wouldn't be involved with. That's just why the NEC has that requirement.
Unfortunately, yes. But it's not so much because of having two GFCIs on the same circuit. It's because of a ground test that the charging cable does. It trickles a tiny bit of current onto the ground pin to see if it seems to be floating (bad) or is tied hard to ground at 0V (good). Unfortunately, that is exactly the kind of condition that GFCI is looking for and attempting to prevent, where current is not exactly matched on the two voltage pins. The current used for that ground test is very tiny, and is supposed to be below the threshold that the GFCI would trip at, but that threshold level is also very tiny and close to that testing amount. So if the GFCI breaker is a little out of spec, it can have nuisance trips from that ground test.
It's kind of a pain, but that's what the code requirement is, and is yet another reason why the wall connector is getting to be a better choice, because those hardwired ones don't need to have that touchy and expensive GFCI breaker.
The solution isn't great. If the GFCI breaker is a bit out of spec and doing this initially, or drifts out of spec in a few years and starts doing it, you need to replace it with a newer one that hopefully is in spec and stops doing that.
Mostly yes. I'm not sure if all brands of those mobile charging cables (like J1772 plug ones) also do that ground test or not. If they do, then they would run into this same problem.
Yeah, some people just don't have this problem come up if they happen to get a good GFCI breaker that stays within spec for a long time. But they are very touchy and sensitive, so the rate of people who do run into problems with it is annoyingly high.
I have a question about installing a charger. I'm in a unique situation where my install is pretty straightforward as far as running cable. My main breaker is in the basement and it can be ran across the ceiling under a crawl space, up beside my main plumbing pipe to an access panel in my attached garage for my bathroom plumbing. It's about 30 feet total and I'm wondering if I just run an extension cord would it be fine.
No, it's not fine. Extension cords are not a decent substitute for doing an actual wire run with solid, screwed in connections. And how would you just plug an extension cord into your electrical panel? Nevermind--I probably don't want to know. Get a load calculation to see how big of a new circuit you can add and get a real circuit added that goes to your garage.
Yes no, I'm not that dumb lol. I'm sorry but maybe I wasn't clear. I was saying the install is pretty straightforward as far as hardwiring a new line would go...as far as the extension I was talking about from my already existing 240 dryer plug.
davewill
Active Member
You certainly weren't. You never mentioned a 240v dryer plug, just running wire from the basement to your garage.
In general, I say NEVER use an extension cord for a permanent charging solution. There are a couple of ways that can go wrong (bad connection, kicking/tripping), so why chance it? Nor am I fond of sharing a circuit (like the dryer circuit) if that means plugging and unplugging a lot.
Since your install is so "straightforward" you should just install a proper circuit.
Our 2018 Model 3 long range is charged at home 99.9% of the time. Charge is set at 35 amps on a wall charger at night during "off peak" hours primarily in the winter when our Tesla Solar Panels are not generating sufficiently as they do in the Summer months. I'm not sure regular quick charging will get you best battery life?
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