Nema 14-50 hoarders
- Thread starter 2101Guy
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dgpcolorado
high altitude member
Leaving aside the fact that many Tesla owners have been using 14-50 outlets and the MC as their main car charging for years, without difficulty, an advantage of having the 14-50 adapter is that you can use it to charge at RV parks and most state park campgrounds, something I have done dozens of times on more than 50k miles of road trips. [It is also helpful to carry a TT-30 adapter for "30 amp" service campgrounds; Tesla doesn't make one but they can be made as DIY or purchased from third parties. TT-30 (120 V, 30 A — requires limiting the car charging to 24 amps) is slow but useful when camping overnight. The main campground at Zion National Park has TT-30 pedestals.]
^ Campground pedestal at Dead Horse Point State Park in Utah (adjacent to Canyonlands National Park near Moab). The 14-50 outlet is on the left and a TT-30 is in the center.
My 2¢ as an experienced road tripper.
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Many places that sell RV supplies will have a TT-30 Male to 14-50 Female adapter. All of us with fifth wheel campers carry on in our rig. 120v 30A won't be a speedy charge though.
The adapter you describe will not provide any voltage across the two hots on the 14-50 that are used for EV charging. Even if re-wired, it would not set the max current correctly. For TT-30, it is best to get a proper UMC adapter (e.g., from evseadapters) that also automatically sets the current to 24 amps max.
Man, I can't believe I didn't think about that. Those adapters put the single phase on both legs. Works fine for my RV, but will yield 0 volts to the tesla. Thanks for correcting that!
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MrMassTransit
Supporting Member
While frustrating, Tesla deserves some blame here. Keeping 14-50s and many other items in stock is an issue that has gone on for a over year and perhaps longer (I just didn't have a Tesla prior to that time!). This is not a temporary shortage by scalpers buying massive amounts of inventory for resale. Tesla has consistently failed to produce enough of these to keep them in stock and regularly runs out of HPWCs, CHaDeMo adapters and many other items. At most, there's a few dozen of these on eBay. I realize producing cars is their primary focus, but it would be nice if they could work on building a reliable supply chain for accessories.
Alternatively, they could simply take backorders, so items would ship as soon as they become available instead of making people scramble as soon as an item is back in stock and an e-mail goes out. A backorder system would also let them see the true demand for an item, allowing them to adjust production, and would probably reduce some anxiety around supply, drying up order for resellers.
The coronavirus situation involves people taking advantage of an unforeseen crisis, which the availability of charging equipment is definitely not - it is has been a longstanding and predictable concern.
Alternatively, they could simply take backorders, so items would ship as soon as they become available instead of making people scramble as soon as an item is back in stock and an e-mail goes out. A backorder system would also let them see the true demand for an item, allowing them to adjust production, and would probably reduce some anxiety around supply, drying up order for resellers.
The coronavirus situation involves people taking advantage of an unforeseen crisis, which the availability of charging equipment is definitely not - it is has been a longstanding and predictable concern.
Electric Steve
Member
Totally agreed. I'm trying to buy the longer-cable version of the Wall Charge but it's out of stock. I signed up to be notified by email when it becomes available. That came, but it sold out immediately. Now I'm waiting again.
This is silly.
rhumbliner
Member
When you make preposterous claims it be nice if you would quote the relevant section in the NEC.
iamnid
Member
Yeah, I think they are referring to 10-30 which got deprecated because it doesn't have a ground. 6-50 is EXACTLY the same as far as safety goes as a 14-50. The difference is that it has 2 hots and a ground but lacks the neutral of the 14-50. The neutral on the 14-50 is so RVs can get 120v from the port in addition to 240v - the Tesla doesn't even use the neutral when you use a 14-50. But, whatever, people know what they know. I was just suggesting an alternative that would work perfectly until the 14-50 is back in stock (and that would only be useful to have if you are going somewhere that has those outlets available like an RV park).
And what do you do with the remaining wire? In this case, the neutral... Yeah, I know you can disconnect it at the panel and nut it off
It actually is true that most new residential installations are not allowed to install a 6-50. If it’s pre-existing or the wiring / panel exists to support it / there’s no common or neutral wiring, then fine. You won’t find it in a new home built in North America in the last 8 years or so. And if you’re in an area that requires a permit and inspection for 50A circuits, you’ll never get permitted or pass an inspection with a 3-wire 6-50 plug if your existing panel and home wiring can accommodate the 14-50. There are some areas still using UBC or IBC from like 15 years ago that may allow it still.
As for the reasoning behind this, I suppose it just has to do with having the neutral wire.
which section of the NEC code requires Nema 14-50?
I have never read that this was in a uniform code across all of the USA and i've read many many posted topics about 14-50 and 6-50.
Not sure where it’s at the code or which revision. I’m a general contractor who builds custom homes here and there and my electricians have told me this and I use two different electrical contractors. Perhaps the restrictions are more localized, I’m in Colorado.
MrMassTransit
Supporting Member
Interesting. We're on the 2011 NEC here in DC and 6-50s are no problem. I have a copy of the 2020 NEC on my desk but I can't start hunting for something that may or may not be present. I've never heard of a restriction on 6-50s either.
That being said, I can understand why most builders are installing a 14-50 over a 6-50. Having the neutral provides a bit more utility if a customer wanted to use the outlet for purposes beyond EV charging. Additionally, multiple electric cars (such as the new Nissan Leaf) come with 14-50 adapters, so it has become a bit of an informal standard.
It's all a moot point, though - the 6-50 adapter is also sold out on Tesla's site.
That being said, I can understand why most builders are installing a 14-50 over a 6-50. Having the neutral provides a bit more utility if a customer wanted to use the outlet for purposes beyond EV charging. Additionally, multiple electric cars (such as the new Nissan Leaf) come with 14-50 adapters, so it has become a bit of an informal standard.
It's all a moot point, though - the 6-50 adapter is also sold out on Tesla's site.
A 6-50 is commonly used for welding gear. It is perfectly fine in new construction when a neutral connection is not needed. The ones that are obsolete are the 10-series (e.g., 10-30 and 10-50). No safety ground connection. The 10-series have not been legal for new construction since 1996.
NEC 2017 requites a neutral for a range. IE one is required to install a 14-50 instead of a 6-50 these days at least for a range...
Why use the HPWC unless you work in a job with night standby, like doctor or hitman? The constant 72A charging as opposed to 30A from NEMA 14-50 via a UMC with a wall bracket will decrease your battery life faster.
Been five years now with my MS and always have two UMCs, these also fail and the spare one is a Godsent if you live 100mi from the metropolis.
Oh and all my 3 garages have 14-50s with a fourth on the outside wall for those PlugShare visitors from the past and future family visits once all cars become EVs. A 22kW gas generator will make sure the BEVs get juice even after the gasoline pumps fail after a prolonged power outage, less than 10% of US gas stations have generators.
Been five years now with my MS and always have two UMCs, these also fail and the spare one is a Godsent if you live 100mi from the metropolis.
Oh and all my 3 garages have 14-50s with a fourth on the outside wall for those PlugShare visitors from the past and future family visits once all cars become EVs. A 22kW gas generator will make sure the BEVs get juice even after the gasoline pumps fail after a prolonged power outage, less than 10% of US gas stations have generators.
True. That is because in a range the main heating coils run on 240V, but the timer and whatnot run on 120V. So the neutral is required for the 120V portion. Same with an electric clothes dryer and 14-30. With EV charging at 240V, neutral is not used. So a 6-50 is fine.
Electric Steve
Member
As both a doctor and a hitman (I work both sides of the game), I have to disagree.
I don't believe there's a substantial decrease to battery life from charging with a WC. Even SuperCharging doesn't destroy your battery life. If you really believe this, you'd always trickle-charge at 110V unless you're in a hurry.
Anyhow, Tesla knows this, which is why their official recommendation is to install a WC.
azjohn
Member
And if for some reason that ever happened which I doubt, EVSE adapters sells a 14-50/6-50 adapter
MrMassTransit
Supporting Member
Two practical reasons:
1. For outdoor installations, the HPWC is a bit better suited to charging in all weather (why I have one) and is less at risk for theft or tampering (only a real issue in very cold whether when the connector does not lock to prevent it from freezing in place).
2. If the load sharing capability is needed
There’s no need to use the full capacity of the HPWCs, also. The new model only supports up to 48A, anyway. Mine is on a 30A circuit - I have it to have a nice looking outdoor charging option, not for the higher power.
