Mobile Connector Gen 2 using NEMA 6-50

[Steinmetz]

Hello!
I have a new model X on order and I am considering my home charging options. The vehicle comes with a Mobile Connector that looks like it can be configured to provide a 240VAC, 32 Amp output, when using a 50 Amp breaker circuit. I already have this circuit and connector in my garage for use by my welder. What is the down side to doing this other than I would not have the Mobile Connector in the car all the time unless I unplugged it and put it in the Frunk. I realize using a Wall Connector can get me 30 MPH as opposed to the above which gives 20 MPH. Not sure that is worth the $500. The Optional Adapter for the Mobile Connector NEMA 6-50 is $35. It comes with a NEMA 5-15.

 

[TiggerTime]

If you can run a NEMA 14-50 plug off that 50A line then your mobile connector will give you 30mph charge as well. You just wouldn't be able to run the welder and charge at same time.

 

[ajdelange]

Hello!
I have a new model X on order and I am considering my home charging options. The vehicle comes with a Mobile Connector that looks like it can be configured to provide a 240VAC, 32 Amp output, when using a 50 Amp breaker circuit. I already have this circuit and connector in my garage for use by my welder. What is the down side to doing this other than I would not have the Mobile Connector in the car all the time unless I unplugged it and put it in the Frunk.

That's it. Some guys will buy a second mobile charger and leave it plugged in at home so that there is always a charger in the car. That costs a bunch of bucks to the extent that you might reconsider the HPWC.

I realize using a Wall Connector can get me 30 MPH as opposed to the above which gives 20 MPH. Not sure that is worth the $500. The Optional Adapter for the Mobile Connector NEMA 6-50 is $35. It comes with a NEMA 5-15.

In a nutshell the story is that EVSE is considered a continuous load and so may only take 80% of the installed breaker's capacity. For a 50 amp circuit that is 40 A. Most installations put a 14-50R receptacle on a 50 A circuit but due to a quirk in the code it is allowable to put a 14-50R on a 40 amp circuit too. In an abundance of caution, probably suggested by their lawyers, Telsa reduced the draw the Gen II charger requests with the 14-50P pigtail to 32 A i.e. 80% of 40 A. I would have guessed that going to a 6-50R receptacle would get you the extra 8 amps as I don't think you can put a 6 - 50R on a 40A circuit but the table in the Tesla catalogue indicates the same charge rate for this adapter as for the 14-50R. So I suppose this connector is limited too. OTOH I note that the webpage listing for the wall charger says the maximum it can deliver is 11.5 kW when in fact it delivers 17 kW to mine.

In any case 20 mph means a full charge in 16 hrs and you will never charge it that much at home. 40% to 75% is probably typical for most users. Be comforted by the fact that gentle charging will extend the battery's life.[/QUOTE]

 

[SSedan]

If you can run a NEMA 14-50 plug off that 50A line then your mobile connector will give you 30mph charge as well. You just wouldn't be able to run the welder and charge at same time.

Why run a 14-50 plug as opposed to just buying the 6-50 adapter?

On the charge rate you are missing the Model X critical fact which makes you wrong and the OP right.

Personally I like to have a backup charging plan. I went wall connector so the UMC is the backup, but a second UMC can accomplish that or a nearby public option.

I like having a home solution that gives me maximum rate on the rare occasion I need it. In my case we got a call about a family emergency while on vacation, rushed home and right back out and had to hit a supercharger on the way to meet my parents at the hospital. Had I had a high amperage Wall Connector I would have avoided the extra stop. The wall connector was ordered and I stalled weeks later.

 

[ewoodrick]

Should be fine. I have a second UMC, which is half the price of a HPWC.

 

[Hebert]

I think your post thoughtfully details the pros and cons. I use a mobile connector to charge my X at home. It charges at 22 mph which is faster than I need.

It would be good to double check the wire gauge/type, circuit breaker and the welder plug to see if they all rated at 40amps to verify you can put a 32 amp load on the circuit.

You can always change your mind later and invest in a quicker charge rate.

 

[Steinmetz]

Thanks to all for your replies. It all makes sense, except perhaps the 32 Amp limit but as stated it appears to be Tesla rules, not NEC. The branch circuit is wired from a 100 Amp sub panel with 6ga THWN. It appears that at one time Tesla provided a 14-50P adapter. Was there a time when a neutral was required, or why not a 6-50P?

 

[power.saver]

Neutral is not required. The 14-50 was provided because that receptacle is common for electric dryers. You can use the 6-50 instead.

 

[NickFie]

Was there a time when a neutral was required, or why not a 6-50P?

Our 2017 S100D Gen 1 Mobile Connector came with 6-50 P adapter. A friend loaned me a 50-foot welder’s extension cord. I’ve purchased or cobbled together various adapters for the cord. Very handy when a dryer outlet is the only substantial power source, and it’s distant from parking or garage.

Must remember to dial down dryer plug charge rate to 24 Amps before starting to charge.

You could probably make a heavy-gauge cord with 6-50 plug on one end and 14-50 receptacle at the other.

 

[ajdelange]

Was there a time when a neutral was required, or why not a 6-50P?

The neutral is still not required. A true 240V load requires only the two hots and earth. Clothes dryers were often plugged into receptacles that had only those three wires. As time progressed they started adding lights, timers, bells and whistles that took small amounts of 120V and so the NEC had an exception that allowed the ground to be used as neutral for this application. That's since been deprecated and dryers now require two hots, and neutral.

The Tesla charger is a true 240 V load. It has no 120 V circuits in and does not need a neutral. However it has been my experience that whenever I have run 14/2 or 12/2 ...for a 240 V circuit I have subsequently regretted that I did not pay the couple of extra bucks to run 14/3 or 12/3... as eventually something has come up where I wanted 240 and 120 out of that circuit. When I have had the 3 conductor (plus earth) cable run I have puzzled electricians but as it's kerching for them and they usually comply. When I had the cable pulled for my HPWC they pulled SE (which is 3 conductor) and the guy said "What do you want me to do with the neutral" and I said "Land it". He wanted to cut it off. I don't know what I may do with that line in the future but were I to, for example, put a sub panel there, I would certainly want the neutral.

The reason for wanting a 14-50R rather than a 6 - 50P is that you don't know what you may want to plug into that outlet at some future time. The 14 - 50R has you covered.

 

[Rocky_H]

The 14-50 was provided because that receptacle is common for electric dryers.

Clothes dryers do not use 14-50 outlets; you are thinking of 14-30.
Tesla's choice for 14-50 outlets was for enabling traveling before they had begun to create Superchargers. There are campgrounds and RV parks all over the United States. Those 14-50 outlets are the outlet that those campgrounds have for the big mobile homes. I did some traveling early on with those outlets at campground places before I had Superchargers in range.

 

[ajdelange]

The cars used to come with a 14-50R adapter in the kit. They don't now, apparently. $10 less on Tesla's negative cash flow. They are pretty prevlent. Check PlugShare. Most of the listed ones are at camp grounds but quite a few are found in garages, at welding shops, auto dealerships, truck stops, marina's etc. There is even one in many homes behind the stove be it gas or electric (I have one behind my gas stove) though this is not really a convenient place to charge. When I travel off the SC net (Canada) I always have a 14-50P adapter for the UMC and a 50' 14-50 extension cord on board though I have never used either (UMC or extension cord) of them except at home.