Why 14-50 over 6-50 outlets?

[XrstalLens]

It looks like Tesla provides both 6-50 and 14-50 adapters for the chargers. As I look for how to prepare for my Model S, I'm wondering why they seem to strongly recommend the 14-50 over the 6-50 for new installations. Is it just for compatibility reasons with other devices/future vehicles? The Model S does not use the neutral, and I'm looking at using 6 AWG MC (armored flex conduit) to put in my run. The 6/3 is twice as expensive as the 6/2 cable, so would be nice to save on the cost.

I definitely plan on getting a 14-50 adapter for use in campgrounds, etc., but at home I'm wondering why I would need to run the extra wire for a 14-50?

 

[mitch672]

You have it correct, the 14-50 recommendation is because of RV Parks.

It could be cheaper for you to buy both the 6-50 for your home wiring, and buy a 14-50 for use at RV Parks.
It really depends on the length of your wire run, in my case it was only 20' in PVC pipe, so just 1 extra THHN conductor added for the Nuetral.

 

[Arnold Panz]

The only reason to do a 6-50 (and the only people who get 6-50 adapters) are for the HPWC, which isn't ready yet. But the wiring is the same (and more complex than for the 14-50), so the only reason to do the 6-50 is if you eventually will put in a HPWC. Otherwise, you can just do the 14-50 and be done with it. Cheaper, and more compatible with other things. And Tesla won't give you the 6-50 adapter unless you order the HPWC.

 

[XrstalLens]

The only reason to do a 6-50 (and the only people who get 6-50 adapters) are for the HPWC, which isn't ready yet. But the wiring is the same (and more complex than for the 14-50), so the only reason to do the 6-50 is if you eventually will put in a HPWC. Otherwise, you can just do the 14-50 and be done with it. Cheaper, and more compatible with other things. And Tesla won't give you the 6-50 adapter unless you order the HPWC.

Why would the 6-50 be more complicated and more expensive? The 6-50 only uses 2 wires plus ground, while the 14-50 has 3 wires + ground. The reason they say that for the HPWC is precisely because there is no need to run a neutral wire for either the 6-50 or HPWC. However, I have no plan to get a HPWC, but neither do I need a connection with a neutral - my wire run will be lengthy and the extra wire is just extra cost for something I won't use.

 

[Arnold Panz]

Why would the 6-50 be more complicated and more expensive? The 6-50 only uses 2 wires plus ground, while the 14-50 has 3 wires + ground. The reason they say that for the HPWC is precisely because there is no need to run a neutral wire for either the 6-50 or HPWC. However, I have no plan to get a HPWC, but neither do I need a connection with a neutral - my wire run will be lengthy and the extra wire is just extra cost for something I won't use.

I'm just telling you what the electrician told me. I don't have a clue about this stuff. I wouldn't be sure that Tesla will give you a 6-50 adapter, although I expect you can buy it from them. I think only people waiting on an HPWC get the adapter free while we wait for the HPWC, and the instructions from Tesla were clear that for the HPWC we need to install a 6-50, but otherwise they recommend a 14-50 if you are only going to use the mobile connector.

 

[mitch672]

The only reason to do a 6-50 (and the only people who get 6-50 adapters) are for the HPWC, which isn't ready yet. But the wiring is the same (and more complex than for the 14-50), so the only reason to do the 6-50 is if you eventually will put in a HPWC. Otherwise, you can just do the 14-50 and be done with it. Cheaper, and more compatible with other things. And Tesla won't give you the 6-50 adapter unless you order the HPWC.

As I said, factor in the cost of the extra conductor in your wire run versus the COST of you BUYING and PAYING for an extra adapter, which is rumored to cost about $75 to $100. The adapter could cost less than the extra conductor, depending on the length of your wire run & method, that was my point. Tesla doesn't give you anything, you pay for an extra adapter.
You might not be buying a HPWC either, some people will be fine with just the supplied portable EVSE, and are just looking to save money on their installation.

 

[XrstalLens]

... but otherwise they recommend a 14-50 if you are only going to use the mobile connector.

My question is why they recommend this. It sounds like it's just for compatibility reasons (i.e campgrounds). Since both the wiring and connector are substantially cheaper for the 6-50 I'll probably put that in my garage as well as my Dad's, and just buy the 14-50 adapter from Tesla for use at campgrounds. Whichever adapter Tesla will give me I'll take, and I'll buy the other one. I figure I can save at least $350 by putting in the 6-50 vs a 14-50, more than the cost of the extra adapter.

 

[FlasherZ]

My question is why they recommend this. It sounds like it's just for compatibility reasons (i.e campgrounds).

That is correct. The charger does not use the neutral lead in a NEMA 14-50 plug (it's unconnected in the UMC) and therefore to the car the 6-50 and 14-50 are equivalent. It's a matter of the 14-50 being more prevalent in RV parks.

I want both adapters, because 6-50's are more prevalent in machine shops, which I also frequent occasionally (including mine).

 

[Cottonwood]

It looks like Tesla provides both 6-50 and 14-50 adapters for the chargers. As I look for how to prepare for my Model S, I'm wondering why they seem to strongly recommend the 14-50 over the 6-50 for new installations. Is it just for compatibility reasons with other devices/future vehicles? The Model S does not use the neutral, and I'm looking at using 6 AWG MC (armored flex conduit) to put in my run. The 6/3 is twice as expensive as the 6/2 cable, so would be nice to save on the cost.

I definitely plan on getting a 14-50 adapter for use in campgrounds, etc., but at home I'm wondering why I would need to run the extra wire for a 14-50?

All of your reasoning is quite sound. The only reason to put in the 14-50 is that is more useful for other purposes. These include plugging in your friend's RV when they visit, plugging in another EV (like a Roadster that has a 14-50, but not a 6-50 adapter), and things like the breakout box my electrician has that plugs into a 14-50 and provides 8 separate 120V, 20A circuits each with its own 20A breaker.

It is a simple tradeoff. The 6-50 is cheaper to install, and the 14-50 is more versatile for other uses. Both will charge the S at 40 Amps.

Good Luck!