Installing a Nema 14-50 on a 30 Amp Breaker

[SoundDaTrumpet]

Yeah, if you can get a 14-50 adapter for the Gen 1 UMC that signals only 32 amps to the car (was this for the Canadian thing? or does this not actually exist) then you could install a 14-50 receptacle on either a 40 or a 50 amp circuit and be code compliant. The load calc is done based on the intended load, so if it is 32a continuous then you calculate it as 40a of load regardless of the actual circuit being 40a or 50a. So I would generally always do it as 50a...

Of course this does set up a situation where a future owner could go plug a different EVSE in at 40a continuous and blow the load calculations... But from what I understand this is how the code works. Maybe we need a change to the code that forces you to calculate receptacles like this at their max available supply rather than based on what you intend to connect to them.

I realize much is intended load. The problem is that fire safety extends beyond tenant/homeowner cognizant/responsible for the receptacle (i.e. you move away or plain forgot about it). EV charging takes these one rarely plugged/unplugged appliances (e.g. stove / dryers) and presents them as convenience sockets for the EV revolution. I would conclude please use a #6 wire to cover all bases. A 30A circuit breaker (e.g. MP230) can accept #6 wire. The NEMA 14-30 accepts wire as large as a #4.

I did install using a GFCI. Those are pricey. Money is better spent bridging the money gap to do a hardwired Wall Connector. One less receptacle that you have to wrestle with get thick wire into a two gang box. The Wall Connect can be officially turned down lower amps which is the KEY feature.

 

[miimura]

Or just put the 50 amp breaker on it and be done with it. If 10A is going to break the bank they really need to rethink what they have running in their house.

Also The gen1 and 2 adapters aren't compatible

If you want it to pass inspection, you have to put the 40A breaker. The OP already said that was all the load calc would allow. If you're advocating changing the breaker after the inspection, you should clearly say so. I would not bother because the Model 3's Mobile connector won't do anything different, but I would label the 14-50 socket to say it has a 40A breaker.

 

[LCR1]

What load calculation? Just tell them what you want installed and let them install it.

 

[eprosenx]

If you want it to pass inspection, you have to put the 40A breaker. The OP already said that was all the load calc would allow. If you're advocating changing the breaker after the inspection, you should clearly say so. I would not bother because the Model 3's Mobile connector won't do anything different, but I would label the 14-50 socket to say it has a 40A breaker.

I am not sure this is true.

If the load to be served is a UMC Gen 2 then on a 14-50 it’s max draw is 32a continuous. So you calculate that as 40a of draw.

Whether you breaker the circuit at 40a or 50a I don’t think will actually impact your load calculations.

 

[Dutchie]

I use 14-30 and set load to 24A. Works perfectly. Maybe twice or three times in the two years since I own the car that it wasn't charged to 80% in the morning when I left. Even these times I had ample charge to go through the day.

Still thinking of getting a home charger though. I have to use an heavy duty extension cord to get to the outlet and the whole set-up, while it works, isn't very tidy.

 

[eprosenx]

I use 14-30 and set load to 24A. Works perfectly. Maybe twice or three times in the two years since I own the car that it wasn't charged to 80% in the morning when I left. Even these times I had ample charge to go through the day.

Still thinking of getting a home charger though. I have to use an heavy duty extension cord to get to the outlet and the whole set-up, while it works, isn't very tidy.

So on the end of your extension cord are you using a 14-30 or a 14-50 adapter? Basically I am curious if the car hard limits you to 24a or if it lets you go to 32?

My standard advice is to not use an extension cord when charging at home. If you look at the fire cause statistics extension cords are just horribly dangerous. I highly recommend not using them when charging at home. It is worth it to have a solid solution.

Also, as per this thread, we don’t recommend relying on the user setting to a lower amperage in order to safely charge. Having the proper maximum set by the Tesla adapter you use is worth a ton safety wise.

 

[Dutchie]

So on the end of your extension cord are you using a 14-30 or a 14-50 adapter? Basically I am curious if the car hard limits you to 24a or if it lets you go to 32?

My standard advice is to not use an extension cord when charging at home. If you look at the fire cause statistics extension cords are just horribly dangerous. I highly recommend not using them when charging at home. It is worth it to have a solid solution.

Also, as per this thread, we don’t recommend relying on the user setting to a lower amperage in order to safely charge. Having the proper maximum set by the Tesla adapter you use is worth a ton safety wise.

Bought this Heavy-duty NEMA 14-50R extension cord for Tesla, 20 ft.

And the adapter on the end where car charger goes. Always charges @ 6kW. I always check. The user setting is always 24 A when charging at home.

 

[mcfuzz89]

I am actually in the same boat - however my laundry nook is in the house. So my plan is to disconnect the outlet in the laundry nook, install a 50 amp breaker (assuming my electrician confirmed wiring can support it) and then wire a wall charger to that circuit.

 

[BrokerDon]

I'm just waiting for the 1st electrical fire on one of these "questionable" installations... then the owner to claim "Tesla caused a fire" post and lawsuit to follow shortly thereafter.

Intelligent answer is to:

1. do a "Load Calculation" required by your local building department
2. pull an electrical permit from your local building department with the properly filled out "Load Calc"
3. pay a LICENSED electrician install your charger outlet per the "Load Calc"... and have him SIGN the permit and write in his license number
4. have the charger outlet inspected and signed off by your local building department

... so you can sleep well at night AND not provide attorneys and your homeowner's and auto insurance companies a "cause for action" to sue you and void your insurance.

Sure it's not EASY but it IS the only way to do it CORRECTLY and not subject yourself to serious liability.

 

[Dutchie]

I'm just waiting for the 1st electrical fire on one of these "questionable" installations... then the owner to claim "Tesla caused a fire" post and lawsuit to follow shortly thereafter.

Intelligent answer is to:

1. do a "Load Calculation" required by your local building department
2. pull an electrical permit from your local building department with the properly filled out "Load Calc"
3. pay a LICENSED electrician install your charger outlet per the "Load Calc"... and have him SIGN the permit and write in his license number
4. have the charger outlet inspected and signed off by your local building department

... so you can sleep well at night AND not provide attorneys and your homeowner's and auto insurance companies a "cause for action" to sue you and void your insurance.

Sure it's not EASY but it IS the only way to do it CORRECTLY and not subject yourself to serious liability.

Don't see the issue. All products used are specifically designed and used for the application needed.

 

[LCR1]

I'm just waiting for the 1st electrical fire on one of these "questionable" installations... then the owner to claim "Tesla caused a fire" post and lawsuit to follow shortly thereafter.

Intelligent answer is to:

1. do a "Load Calculation" required by your local building department
2. pull an electrical permit from your local building department with the properly filled out "Load Calc"
3. pay a LICENSED electrician install your charger outlet per the "Load Calc"... and have him SIGN the permit and write in his license number
4. have the charger outlet inspected and signed off by your local building department

... so you can sleep well at night AND not provide attorneys and your homeowner's and auto insurance companies a "cause for action" to sue you and void your insurance.

Sure it's not EASY but it IS the only way to do it CORRECTLY and not subject yourself to serious liability.

1) There are no load calculations required where I live.
2) there are no building permits where I live
3) licensed doesn’t mean anything. Look at any one doing anything with a “license”
4) There is no building department and no building codes.

So yea, your way IS NOT the only way to do it CORRECTLY. thanks for playing though.

 

[BrokerDon]

1) There are no load calculations required where I live.
2) there are no building permits where I live
3) licensed doesn’t mean anything. Look at any one doing anything with a “license”
4) There is no building department and no building codes.

So yea, your way IS NOT the only way to do it CORRECTLY. thanks for playing though.

Actually I didn't say it was the ONLY way. I said it was the INTELLIGENT way.

Seems like Texas has adopted the 2017 National Electrical Code: NEC® adoption maps - NFPA which makes me wonder where in Houston Texas you live that magically is exempt from the state adopted National Electrical Code. Mexico?

There are definitely alternate "less intelligent" ways to connect and use electrical wiring... which is why there are WARNING labels on just about everything these days like hair dryers "Do NOT immerse in water". NOT intelligent, but definitely an option.

But hey it's a free country and everybody can do anything the way they want... including ignoring the National Electrical Code... which almost assuredly does require people doing an EV charging circuit installations to:

1. do a "Load Calculation" required by your local building department
2. pull an electrical permit from your local building department with the properly filled out "Load Calc"
3. pay a LICENSED electrician install your charger outlet per the "Load Calc"... and have him SIGN the permit and write in his license number
4. have the charger outlet inspected and signed off by your local building department

Sure nobody can MAKE you do this, but failing to do so could put you in the running for a Darwin Awards. Chlorinating The Gene Pool.

 

[eprosenx]

Actually I didn't say it was the ONLY way. I said it was the INTELLIGENT way.

Seems like Texas has adopted the 2017 National Electrical Code: NEC® adoption maps - NFPA which makes me wonder where in Houston Texas you live that magically is exempt from the state adopted National Electrical Code. Mexico?

There are definitely alternate "less intelligent" ways to connect and use electrical wiring... which is why there are WARNING labels on just about everything these days like hair dryers "Do NOT immerse in water". NOT intelligent, but definitely an option.

But hey it's a free country and everybody can do anything the way they want... including ignoring the National Electrical Code... which almost assuredly does require people doing an EV charging circuit installations to:

1. do a "Load Calculation" required by your local building department
2. pull an electrical permit from your local building department with the properly filled out "Load Calc"
3. pay a LICENSED electrician install your charger outlet per the "Load Calc"... and have him SIGN the permit and write in his license number
4. have the charger outlet inspected and signed off by your local building department

Sure nobody can MAKE you do this, but failing to do so could put you in the running for a Darwin Awards. Chlorinating The Gene Pool.

Nice graphic, thanks for posting!

What the he** is wrong with these states?

Does the 2008 NEC even mention *anything* about EV’s? I wonder if their baseline code is 2008 but they have added a ton of custom exceptions to bring some things up to handle modern needs?

I am actually shocked California is still on 2014!

 

[BrokerDon]

Nice graphic, thanks for posting!

I am actually shocked California is still on 2014!

California has created their own "electrical code" with latest revision of their "Title 24 Energy Efficiency" regulations with (no I'm not kidding) 2,000+ pages of CA specific energy codes including electrical, HVAC, insulation, etc.

2019 Building Energy Efficiency Standards - California Energy Commission

Coming January 1st, 2020 most new construction will be required to be "Net Zero" energy usage pretty much making solar and high efficiency construction mandatory including providing breaker space and a 1" conduit run to a junction box inside the garage for EV charging. Major homebuilders like Lennar are already building "Net Zero" houses now.

The unintended effect of this has been to make new housing more expensive = less affordable. Painful for first time home buyers but ultimately probably a good thing.

 

[LCR1]

Actually I didn't say it was the ONLY way. I said it was the INTELLIGENT way.

You did say it and here's your quote in case you forgot

Sure it's not EASY but it IS the only way to do it CORRECTLY and not subject yourself to serious liability.

Seems like Texas has adopted the 2017 National Electrical Code: NEC® adoption maps - NFPA which makes me wonder where in Houston Texas you live that magically is exempt from the state adopted National Electrical Code. Mexico?

You also never mentioned anything about NEC 2017. You only mentioned load calculations and local building departments, none of which apply to where I live. Feel free to highlight anywhere in your statement where you mentioned NEC, here it is again if you need some help.

I'm just waiting for the 1st electrical fire on one of these "questionable" installations... then the owner to claim "Tesla caused a fire" post and lawsuit to follow shortly thereafter.

Intelligent answer is to:

1. do a "Load Calculation" required by your local building department
2. pull an electrical permit from your local building department with the properly filled out "Load Calc"
3. pay a LICENSED electrician install your charger outlet per the "Load Calc"... and have him SIGN the permit and write in his license number
4. have the charger outlet inspected and signed off by your local building department

... so you can sleep well at night AND not provide attorneys and your homeowner's and auto insurance companies a "cause for action" to sue you and void your insurance.

Sure it's not EASY but it IS the only way to do it CORRECTLY and not subject yourself to serious liability.

 

[Dutchie]

You know there are guys who asks there girlfriend to take the birth control pill, asks her to have an IUD implanted and still use a condom while having sex...ie Overly cautious

 

[LCR1]

You know there are guys who asks there girlfriend to take the birth control pill, asks her to have an IUD implanted and still use a condom while having sex...ie Overly cautious

I have a friend that got prego with the pill and condoms. whored out for years unprotected and nothing, goes the extra mile and bam!!! My cousin was also born 13 years after a vasectomy

 

[wcorey]

You know there are guys who asks there girlfriend to take the birth control pill, asks her to have an IUD implanted and still use a condom while having sex...ie Overly cautious

There are things a condom can do that pills and IUDs can't do. Need I say more?

 

[BrokerDon]

You did say it and here's your quote in case you forgot




You also never mentioned anything about NEC 2017. You only mentioned load calculations and local building departments, none of which apply to where I live. Feel free to highlight anywhere in your statement where you mentioned NEC, here it is again if you need some help.

Taking the steps I recommended IS the only way to do it CORRECTLY and not subject yourself to serious liability. Feel free to skip steps and ignore the National Electrical Code at your own peril... Just like the Darwin Awards. Chlorinating The Gene Pool. winners ignore common sense and intelligent choices.

I didn't mention that Texas had adopted the 2017 National Electrical Code: NEC® adoption maps - NFPA until you claimed that Houston Houston Texas (where your TMC info states you live) is magically is exempt from your state's adopted National Electrical Code. Still waiting to hear how you're not subject to the 2017 National Electrical Code adopted by your state. Seems unlikely...

 

[LCR1]

Taking the steps I recommended IS the only way to do it CORRECTLY and not subject yourself to serious liability. Feel free to skip steps and ignore the National Electrical Code at your own peril... Just like the Darwin Awards. Chlorinating The Gene Pool. winners ignore common sense and intelligent choices.

I didn't mention that Texas had adopted the 2017 National Electrical Code: NEC® adoption maps - NFPA until you claimed that Houston Houston Texas (where your TMC info states you live) is magically is exempt from your state's adopted National Electrical Code. Still waiting to hear how you're not subject to the 2017 National Electrical Code adopted by your state. Seems unlikely...

Feel free to quote me where I said I was not subject to NEC. I won't hold my breath, because I never said it.

Also, your steps aren't the only way to do it correctly, because those steps don't exist where I live So I can skip all your steps and everything was done correctly.