Two 14-50's on a Romex 6/3 run.

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Toadmanor

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#1
Maybe someone can answer this for me.

I am running 6/3 Romex on a 50 amp breaker with 240 volts. I was running from the wall that comes into the garage from the basement to the wall on the other side of the garage since that is where I would most likely park my M3.

But then I thought it may be nice to have a 14-50 on both walls of the garage. Is it acceptable to put a 14-50 in the middle of the run and another at the end of the run? I would not being using both at the same time but only one at a time.
 
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SwaggerWagon

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#3
One per run/breaker is NEC code I believe (no promises, looked it up a while ago). I did see on another forum where someone got a smart outlet adapter that both outlets are wired through, and the smart part speaks to each other so that only one outlet can be used at a time. Seems like it would be more acceptable since any future home-owner wouldn't have the understand the implications of using both outlets at once (which is a think the impetus for the code in the first place), but still probably frowned upon.
 

Scubastevo80

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#4
I would check local building code - I have a 14-50 in my garage on the way to the final 14-50 which is outside of the garage for driveway charging. I’m using the same wiring gauge as you and the electrical inspector approved it. If you want pics of my setup, PM me.
 

Little1er

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#5
No, one per run.

I wanted to do the same thing, but have 2 outlets in the middle of my garage .I ended up running a 100a subpanel with Aluminum wire, then pulled the 2x 14-50s from that.
 

Scubastevo80

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#6
No, one per run.

I wanted to do the same thing, but have 2 outlets in the middle of my garage .I ended up running a 100a subpanel with Aluminum wire, then pulled the 2x 14-50s from that.
Little1er - I'm fairly certain, as was my electrician and the inspector who was doing this for 20 years, that the code doesn't specify a number of receptacles on a given 50amp circuit - it talks to max amps. I think you're "1 per run" is the consensus based on basic math. If you assume I'm going to pull 42amps on each at any one time, then the breaker will trip, as intended and I should have installed two sep 14-50s on separate lines as you did.

I'm never going to use more than one outlet at a time, and the external outlet is purely for convenience since my wife and kids go in and out of the house through the garage almost exclusively on weekends.
 

Little1er

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#7
Little1er - I'm fairly certain, as was my electrician and the inspector who was doing this for 20 years, that the code doesn't specify a number of receptacles on a given 50amp circuit - it talks to max amps. I think you're "1 per run" is the consensus based on basic math. If you assume I'm going to pull 42amps on each at any one time, then the breaker will trip, as intended and I should have installed two sep 14-50s on separate lines as you did.

I'm never going to use more than one outlet at a time, and the external outlet is purely for convenience since my wife and kids go in and out of the house through the garage almost exclusively on weekends.
This may be true. I am not an electrician or electrical inspector. I did want the ability to run both outlets at the same time or have the option to install a HPWC near that location. Running the sub-panel gave me more flexibility down the road. I guess if you did ever have 2 circuits plugged in drawing more than 50A, the fuse would go
 

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#8
This is where it is beneficial to have the real Tesla wall connector, because two can be installed on the same circuit sized for just one, and they will communicate with each other and reduce power to share the current if they both happen to be in use.
Of course with a 24-foot cable two might not be necessary if it's just for one car. Or just one centrally-mounted 14-50?
Personally I just recommend a significantly less expensive 14-30, even two separate should be cheap.
 

96s46p

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#9
Little1er - I'm fairly certain, as was my electrician and the inspector who was doing this for 20 years, that the code doesn't specify a number of receptacles on a given 50amp circuit - it talks to max amps. I think you're "1 per run" is the consensus based on basic math. If you assume I'm going to pull 42amps on each at any one time, then the breaker will trip, as intended and I should have installed two sep 14-50s on separate lines as you did.

I'm never going to use more than one outlet at a time, and the external outlet is purely for convenience since my wife and kids go in and out of the house through the garage almost exclusively on weekends.
It does, in a residential dwelling you can only have multiple outlets if they are 30a or less. There is one exception for cooking appliances.

If you have a detached garage that doesn't qualify as a dwelling you can put multiple 50a outlets on a circuit.
 

Toadmanor

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#10
This is where it is beneficial to have the real Tesla wall connector, because two can be installed on the same circuit sized for just one, and they will communicate with each other and reduce power to share the current if they both happen to be in use.
Of course with a 24-foot cable two might not be necessary if it's just for one car. Or just one centrally-mounted 14-50?
Personally I just recommend a significantly less expensive 14-30, even two separate should be cheap.
@JWardell two questions:

1) what size wire should I use with a 14-30?

2) I have a spare, from an old hot tub, 50 amp breaker that I intended to use. Should this be changed to a 30 amp breaker?
 

Scubastevo80

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#11
It does, in a residential dwelling you can only have multiple outlets if they are 30a or less. There is one exception for cooking appliances.

If you have a detached garage that doesn't qualify as a dwelling you can put multiple 50a outlets on a circuit.
96s - for fair disclosure, are you an electrician? When I was discussing with my electrician (who specializes in solar installs), he informed me that the NEC codes do not state you cannot have multiple receptacles on one circuit and there is a level or interpretation one can make on the branch-chain circuits topic. I do not have an detached garage, I pulled a permit and my install was approved by the town electrical inspector.

I think there's a lot of potentially incorrect information being perpetuated on this topic, due to the fact that a 50amp breaker and appropriately sized wiring should obviously not be used to charge 2 cars at 42amps at the same time. We will only have one electric car and would only use one outlet at a time. If we were to have two electric cars, my wife would charge outside during the day (before 8pm) and I would charge overnight in the garage (8pm to 6am). Our other option, which we declined to go with, was a heavy duty switch so that power would only be directed to one outlet at any one time.

Toad - best advice is to get a local electrician who knows the local electrical inspector and have them discuss what will or will not be approved for your situation.
 

ADK46

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#12
A 30 amp circuit requires #10 wire, unless the run is very long (that’s a voltage drop issue). Of course, it must be protected with a 30 amp breaker. Breakers are there to protect the wiring, to keep it from getting too hot and setting your house on fire.

[Experienced but not an electrician.]
 

JWardell

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#13
@JWardell two questions:

1) what size wire should I use with a 14-30?

2) I have a spare, from an old hot tub, 50 amp breaker that I intended to use. Should this be changed to a 30 amp breaker?
10 AWG wire for 30 amp. 8 for 40, 6 for 50.
Yes, make sure the breaker is sized for the wire, or smaller. I used 8 gauge for my 75ft run which might help a bit with voltage drop at 30 amp, but really it's so I can upgrade to 40A in the future.
(I actually limit charging to 20A, still a bit nervous with air conditioners and 60 amp panel and service.)
 

96s46p

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#14
210.23 Permissible Loads, Multiple-Outlet Branch Circuits. In no case shall the load exceed the branch-circuit ampere rating. A branch circuit supplying two or more outlets or receptacles shall supply only the loads specified according to its size as specified in 210.23(A) through (D) and as summarized in 210.24 and Table 210.24.

(B) 30-Ampere Branch Circuits.
A 30-ampere branch circuit shall be permitted to supply fixed lighting units with heavy-duty lampholders in other than a dwelling unit(s) or utilization equipment in any occupancy. A rating of any one cord-and-plug-connected utilization equipment shall not exceed 80 percent of the branch-circuit ampere rating.
(C) 40- and 5-Ampere Branch Circuits. A 40- or 50-ampere branch circuit shall be permitted to supply cooking appliances that are fastened in place in any occupancy. In other than dwelling units, such circuits shall be permitted to supply fixed lighting units with heavy-duty lampholders, infrared heating units, or other utilization equipment.

It's pretty clear but if you want to defer to your electrician or inspector and be satisfied with their judgement then that is up to you, IANAE.
 

Scubastevo80

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#15
And there is where the confusion lies - laymen interpreting the Code (myself included, which is why I hired a licensed electrician who spoke to the inspector before the install).

96 - that's the same part of the Code we reviewed. Since I work in legal/compliance and interpret language for most of my day, I am comfortable we are not violating the code. Where there is a circuit supplying 2+ outlets (which ours is), we are only supplying the loads specified in the Table, which states 50amps using 6gauge copper wire - there's no language about a max number of receptacles or outlets on a 50 amp breaker. Regarding (C), this is purely a definition of what is permissible, not what is not permissible. The language does not say "In other than dwelling units, such circuits shall only be permitted to supply fixed lighting units with heavy-duty lampholders, infrared heating units, or other utilization equipment."

Think about your house using multiple 15amp receptacles on a given circuit, using a 30 amp breaker, for example. I guarantee you don't have your circuits limited to 2 receptacles per breaker. Outlets/receptacles are a potential load, not an actual load therefore the circuit needs to be setup as specified in the Code, not based on total potential load of a given circuit.

That's my 2 cents, but again, I'd advise anyone considering doing what I did to get an electrician and inspector on board since my setup is not the norm, which is 1 receptacle per circuit based on how the vast majority of Tesla owners who post on forums.
 

LUXMAN

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#16
10 AWG wire for 30 amp. 8 for 40, 6 for 50.
Yes, make sure the breaker is sized for the wire, or smaller. I used 8 gauge for my 75ft run which might help a bit with voltage drop at 30 amp, but really it's so I can upgrade to 40A in the future.
(I actually limit charging to 20A, still a bit nervous with air conditioners and 60 amp panel and service.)
So have a 60 amp breaker, what size should the wire be? 4?
 
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#18
I have 60 amp breaker and ran a 6/3 romex (~100 ft). The wall connector is set to charge at 48amps, but I have dialed down the charging current to 40 amps after reading the posts in this forum. I rather give some charging time in lieu of safety.
 

garsh

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#19

96s46p

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#20
And there is where the confusion lies - laymen interpreting the Code (myself included, which is why I hired a licensed electrician who spoke to the inspector before the install).

96 - that's the same part of the Code we reviewed. Since I work in legal/compliance and interpret language for most of my day, I am comfortable we are not violating the code. Where there is a circuit supplying 2+ outlets (which ours is), we are only supplying the loads specified in the Table, which states 50amps using 6gauge copper wire - there's no language about a max number of receptacles or outlets on a 50 amp breaker. Regarding (C), this is purely a definition of what is permissible, not what is not permissible. The language does not say "In other than dwelling units, such circuits shall only be permitted to supply fixed lighting units with heavy-duty lampholders, infrared heating units, or other utilization equipment."

Think about your house using multiple 15amp receptacles on a given circuit, using a 30 amp breaker, for example. I guarantee you don't have your circuits limited to 2 receptacles per breaker. Outlets/receptacles are a potential load, not an actual load therefore the circuit needs to be setup as specified in the Code, not based on total potential load of a given circuit.

That's my 2 cents, but again, I'd advise anyone considering doing what I did to get an electrician and inspector on board since my setup is not the norm, which is 1 receptacle per circuit based on how the vast majority of Tesla owners who post on forums.
I don't see how you can compare B and C and not decide that 30a is the upper limit for multiple outlets in a dwelling unless you are trying to read it that way. But if the buck stops at the inspector you can go by what he says. I am never at a loss for qualified person making bad judgements. Since it is allowed in non dwelling it is not strictly dangerous, just designed to save Joe homeowner from himself.
 
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