[US] - Over the Top - the well equipped EV home garage…for those that wish to "over do it"…

[daveo4EV]

Thanks for the information about EVSE in home garage, and future-proofing. Couple of questions.
--I plan to have work done by licensed electrician - info is for my planning. --

1. I understand at least some 220v EVSE units only require 3 conductors. To meet electrical safety and code requirements, should a circuit having a NEMA 14-50 receptacle be wired with 4 conductors or 3? Is either ok for safety and code, or does it depend on what the receptacle -which has contacts for 4 wires - is used for?

2. If I want to start by using a plug-in 40 amp EVSE on a circuit with NEMA 14-50 receptacle, but have the ability in the future to convert that same circuit to a 48 amp hard-wired EVSE requiring a 60 amp circuit breaker, is it ok for electrical safety and code requirements to initially install wiring and circuit breaker sized for 60 amps, but use NEMA 14-50 receptacle and 40 amp plug-in EVSE? (At some point in the future the same circuit could be hardwired to a different EVSE and the receptacle removed.)

4 wire plugs types are un-necessary for North American EVSE’s - plug types like that that are supported by EVSE are provided for compatibility not requirements. NEMA 14-xx plug types are the “modern” versions of NEMA 6-xx plugs and therefore more likely to be found installed in modern homes.

All North American EVSE’s that that are currrently on the market only require 3 wires - 2 hots + ground - but offer 4 wire plugs for easy of use.

+1 for @Jhenson29

upsize the wire gauge - but go with the correct breaker - swapping the breaker later is easy if you ever decide to go hardwired for a future 60 amp charger (48 amp charge rate)

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[whitex]

Thanks for the information about EVSE in home garage, and future-proofing. Couple of questions.
--I plan to have work done by licensed electrician - info is for my planning. --

1. I understand at least some 220v EVSE units only require 3 conductors. To meet electrical safety and code requirements, should a circuit having a NEMA 14-50 receptacle be wired with 4 conductors or 3? Is either ok for safety and code, or does it depend on what the receptacle -which has contacts for 4 wires - is used for?

2. If I want to start by using a plug-in 40 amp EVSE on a circuit with NEMA 14-50 receptacle, but have the ability in the future to convert that same circuit to a 48 amp hard-wired EVSE requiring a 60 amp circuit breaker, is it ok for electrical safety and code requirements to initially install wiring and circuit breaker sized for 60 amps, but use NEMA 14-50 receptacle and 40 amp plug-in EVSE? (At some point in the future the same circuit could be hardwired to a different EVSE and the receptacle removed.)

1. NEMA 14-50 requires 4 conductors. If you only have 3, or want to save on wiring, you can use NEMA 6-50, which requires only 3 conductors
2. Using a thicker wire (lower AWG gauge number) is always ok. However, check with your local code if there are any additional restrictions, such as a requirement for a safety disconnect above certain amperage.

 

[daveo4EV]

@whitex is wise and accurate - listen to this forum member.

 

[WoKe]

Double 22kw charging setup for my carport.
Configured for loadbalancing so they individually can deliver 22kw and when charging 2 cars at the same time they split the available 27kw between both cars. Even when using the maximum available capacity for charging (27kw) that still leaves me 16kw for domestic use (heatpump, cooking, poolheating, etc …)

 

[satchurator]

I just installed the Porsche Wall Charger (80 amps) to use when my Taycan arrives in a couple of months. In the meantime I’m trying to use it to charge my VW ID.4 which can take 48 A. It will only draw 15.5 A from the charger. Any thoughts?

@astrojeff Did your electrician correctly set the amperage for your PWCC? Perhaps there is an indication of this setting in the UI, but if not, switch off your supply at disconnect or circuit breaker, remove the front cover and check the small rotary dial to confirm it’s set to 80A.

@daveo4EV After multiple electricians ghosting me, my PWCC installation is finally happening on Tuesday. Detailed photos to come on another thread!

 

[Jhenson29]

@Tooney For reference, NEC 220.21(B)(1) covers single receptacles on branch circuits and states that the receptacle has to have an amp rating not less than the circuit. This is going to be your requirement for the 50 amp breaker.

@daveo4EV @whitex
I actually can't find any general reference that strictly requires a neutral to be connected on a 14-50 (or a receptacle generally that requires a neutral). If either of you know what it is, please share. Maybe some areas have local codes, or maybe I have just missed the NEC requirement. I've never looked before last night as it never occurred to me to not connect it.

That said, I stand by my original statement that it's going to be required. The inspection isn't just dependent on code. It's up to the local authority having jurisdiction (AHJ) and I find it unlikely that they will pass a 14-50 without a neutral.

@Tooney
Additionally, the issue (for me) is that this lack of connection is not respecting it's interface. Things should not provide an interface if they don't implement them. If they do, they're the wrong tool for the job (should have used a 6-50). If the 14-50 with a missing neutral is repurposed in the future by yourself or a future homeowner, then there could be problems.

 

[Tooney]

Jhenson, daveo, whitex: Thank you for answering my home charging installation questions. Your posts on this and many other Taycan topics have been really useful.

 

[whitex]

@daveo4EV @whitex
I actually can't find any general reference that strictly requires a neutral to be connected on a 14-50 (or a receptacle generally that requires a neutral). If either of you know what it is, please share. Maybe some areas have local codes, or maybe I have just missed the NEC requirement. I've never looked before last night as it never occurred to me to not connect it.

That said, I stand by my original statement that it's going to be required. The inspection isn't just dependent on code. It's up to the local authority having jurisdiction (AHJ) and I find it unlikely that they will pass a 14-50 without a neutral.

First, I'm not an electrician. I am an electrical engineer though. My knowledge of the electrical code is mostly due to work I do for myself, which includes things like adding new circuits to the house, whether just new outlets, AC appliances, a whole house generator, EV chargers, etc. Doing work myself saves me money but more importantly I get the work done the way I want it done which is usually slightly "overengineered", as I've been told by government inspectors who came to inspect my work (yes, in most places in the USA even if you do the work yourself on your own property, the government requires that you apply for a permit first before you start the work, then have an inspector come out to sign-off on it).

Back to your question, while I don't know which code exactly will require the neutral connection in the NEMA 14-50, I'm going to speculate that there is something in the code somewhere that says all terminals of any socket you install must be connected as intended - probably the same place where is says to connect the terminals as per outlet specification, and not for example connect neutral to ground and ground to neutral, which btw would work in many situations, but could be dangerous. Speaking of being potentially dangerous, I can also think of situations where not wiring the neutral wires could lead to dangerous outcomes. For example, if you plug in a device which uses both split-phases (L1 and L2) and neutral (N), that means that device can have loads between L1-N and L2-N. Now, if N is not connected then the 2 loads end up being connected in series between L1-N-L2 (N is not connected, so just connects the 2 loads). Now, if the two loads are not exactly balanced (i.e. equal power draw, therefore equal impedance), then the load with the higher power will experience a higher voltage than the expected Lx-N 120V, up to 240V actually. That could lead to anything from devices burning out, to a possible fire. One such unbalanced load which uses neutral would be an RV, which runs 120V outlets between L1-N and L2-N - having those outlets put out up to 240Vac is probably not going to end well.

 

[Jhenson29]

I'm going to speculate that there is something in the code somewhere that says all terminals of any socket you install must be connected as intended - probably the same place where is says to connect the terminals as per outlet specification,

Well, I had thought maybe so also, but I couldn’t find anything.

The closet thing I can come up with is 110.3(B) which says listed and labeled equipment shall be installed in accordance with instructions from the listing and labeling. Might learn more from UL 498, but I don’t have a copy of that.

not for example connect neutral to ground and ground to neutral, which btw would work in many situations, but could be dangerous.

Yes, that is in there.

 

[daveo4EV]

I never said building code does not require a neutral on NEMA 14-50 - I simply stated that any EVSE sold in North America does not use/require the Neutral for either a NEMA 14-50 or 14-30 plug type.

In fact inspection of the PMC+/PMCC supply cables demonstrate there is not even a neutral conductor in the 14-50 supply cable - so it’s not even wired up in the supply cable engineered by Porsche - and ClipperCreek installation guides go out of their way to mention ”NO NEUTRAL CONNECTION IS REQUIRED OR PROVIDED”…

_IF_ you have a NEMA 14-50 you should have the neutral wires up correctly by a licensed electrician for non-EVSE usage. You simply can’t know how that plug will be used in the future - and there are in fact NEMA 14-50 based devices that when plugged into a 14-50 plug will require a working neutral for safe operation (your RV for example)

if you want to forgo the Neutral then you should get a NEMA 6-50/6-30 plug type - and if you want to use a NEMA 14-50 based EVSE purchase a simple 6-50P to 14-50R pigtail/adapter - it will be useful at home and for any travels.

_IF_ you are installing a particluar plug type - install it correctly and to match building code requirements…

however most/all North American EVSE’s are 3 wire based items: 1 hot, 1 hot, 1 ground - this is the case regardless of them being plug-based or hard wired…

for longer runs I’d recommend NEMA 6-50 plug type since you will save the additional cost of materials on pulling a 4th conductor (copper wire is expensive these days) - and the EVSE doesn’t need/use/require the neutral.

if you do install a 6-50 and want to use your 14-50 EVSE - this adapter should be effective:

ONETAK NEMA 6-50P to 14-50R 240V 50 Amp 3 Prong Male Plug to 50 Amp 4 Prong Female Receptacle Generator Welder Dryer EV Charger Power Cord Adapter Connector

https://smile.amazon.com/ONETAK-Welding-Charger-Connector-Connecter/dp/B07LGLJ26N/ref=sr_1_9?crid=1Y7KN1URJ0HD1&keywords=nema+6-50+to+14-50+adapter&qid=1636901526&qsid=137-6934074-0115537&sprefix=6-50+to+14-50,aps,464&sr=8-9&sres=B088CT4DJ8,B08QVKHT1F,B083LRJ4DP,B088D8WGSN,B07LGLJ26N,B08V16LRG7,B081RGQXMG,B082X57SQW,B07M5CBXJW,B07V7TKZQC,B07QSDM4QN,B08BG67KVX,B07V94TD6P,B07GZBZCYS,B07T2V87K9,B07QVX8YR2,B07THBGGMG,B07TG183HN,B08RBMJJLP,B08P57HQMV

$29

and $29 is way way way cheaper than Porsche charges for the NEMA 6-50 supply cable - if you have a NEMA 6-50 based EVSE and want to use it with a 14-50 plug you encounter while road-tripping - then there is a similar plug to convert the 6-50 to 14-50. For EVSE usage converting between 14-50 and 6-50 plug types is safe and allowed for two reasons:

1. both are 50 amps - so the AMP rating is the same so no need to adjust the PMC+/PMCC to “pull” different amounts of AMPs
2. since the Neutral is used by the EVSE there is no problem with the adapters in either direction

you can do the same thing between 14-30 and 6-30 plug types - but obviously you should have your PMC+/PMCC set to the appropriate amps for a 30 amp circuit (24 amp charge rate)

for mobile EVSE usage you can also carry a NEMA 10-50 adapter - but it would be rare to encounter one of these - but again $40 or less adapter can be found on amazon.

 

[daveo4EV]

Briefly…

Question: If the neutral is _NOT_ used or required by North American EVSE’s, then why are so many EVSE’s sold with a NEMA 14-50 plug type?​

​

Answer: Compatibility/Ubiquity - _IF_ there is a 240V 50 amp plug-based circuit already installed the most common plug-type in North America will be a NEMA 14-50.​

so if you have to flip a coin as an EVSE vendor and decide to which type of plug to ship/manufacture your EVSE with for the North American market - NEMA 14-50 is a safe bet - so most EVSE’s come with NEMA 14-50 plugs for compatibility even though the Neutral blade/connection is not-required/utilized…

honestly once you understand the structure of a 240V circuit - converting a 14-xx plug type to a 6-xx plug type is trivial…

however you should only do this for EVSE’s - other NEMA 14-50 based appliance/devices/products may actually _REQUIRE_ the neutral - so consult with the product manufacturer before assuming all NEMA 14-50 based devices operate this way - it is most likely not the case!

but for North American 240V EVSE’s (EV chargers) only 3 wires are required/used - and other plugs types they support are simply for ease of use/compatibility with common plug-types one is most likely to encounter in commercial and residential usage…

it’s an “installed base” issue - there are lots and lots and lots of existing NEMA 14-50 plugs all over the place…

 

[daveo4EV]

RV parks - lots and lots of RV parks in north america - and motor-homes/trailers and RV’s have 240V/50 amp hookups - so they have power while camping at many many RV parks/campgrounds…

what type of plug will you find in an RV park?

you guessed it!!

NEMA 14-50

turns out the RV industry has effectively made the NEMA 14-50 the default goto most common “standard” for a 240V/50 amp “hook up”

and YES RV’s do in fact require/use the Neutral - they do so to provide 2 120V circuits - a NEMA 14-50 provides RV’s with both 240V & 120V power - and the 120V power requires/utilizes the Neutral - so when plugged into a NEMA 14-50 “hookup” at a KOA campground - the RV can run both 240V appliances (electric oven/Air conditioing) and provide 120V power for household appliances like TV’s and Microwaves and 120V plugs inside/outside the RV…

so we in the EV community have the RV industry to thank for blazing the trail in providing 240V/50 amp infrastructure across North America - and while Road Tripping with various EV’s over the past 8 years i have occassionally been known to book a spot at a RV park where dedicated EV charging infrastructure was lacking, but low and behold there was a campground with RV hookups that I could use to charge my EV while staying at a near by local hotel…

the EV industry is riding the 240V infrastructure built over the decades in support of the RV industry for power hook ups while camping…and NEMA 14-50 _IS_ the plug type of choice for providing power to an RV…

 

[Jhenson29]

I never said building code does not require a neutral on NEMA 14-50

Apologies; I didn’t say, nor did I mean to imply that you did. And I didn’t take your answer as saying that either.

Really, it was just that @Tooney ‘s questions were specifically about electrical safety and code requirements and I felt I was being slightly dishonest by stating it was required without being about to find an actually reference.

Since you and @whitex had also commented, I thought I would just query you guys to see if you knew of a reference for it.

Maybe I’ll post it on an electrical forum later to see, because I am quite curious now.

Thanks.

 

[Tooney]

for longer runs I’d recommend NEMA 6-50 plug type since you will save the additional cost of materials on pulling a 4th conductor (copper wire is expensive these days) - and the EVSE doesn’t need/use/require the neutral.

At what length does "longer run" roughly start, where 3-wire cable and NEMA 6-50 receptacle should be considered?

 

[daveo4EV]

Apologies; I didn’t say, nor did I mean to imply that you did. And I didn’t take your answer as saying that either.

Really, it was just that @Tooney ‘s questions were specifically about electrical safety and code requirements and I felt I was being slightly dishonest by stating it was required without being about to find an actually reference.

Since you and @whitex had also commented, I thought I would just query you guys to see if you knew of a reference for it.

Maybe I’ll post it on an electrical forum later to see, because I am quite curious now.

Thanks.

no harm no foul - and I didn’t take it personally - this discussion (polite and informative in my opinion) is really discussing two searpate issues:

1. functional requirements
2. legal/building code requirements

functionally any EVSE _IN_ north american only required 3 conductors (2 hots + ground)

however local builidng codes and the inconsistency of buildling inspector’s knowledge and enforcement may vary wildly and I always encourage people to conform/meet local building standards/requirements…

in a perfect world all EVSE’s would ship with NEMA 6-50 plugs because that is a 100% match in design and function to their requirements - however as noted in previous posts - there is an “installed based” of NEMA 14-50 plugs so EVSE’s tend to ship with 14-50 plugs to match the common and existing infrastructure - even though they functionally do not require NEMA 14-50

the 14-50 plug type is the most compatible and ubiquitous
the 6-50 plug type is 100% match functionally

any EVSE can use either plug type with right connector or adapter…

functionally it doesn’t matter and once you understand how this all works it easy to go back and forth between the two standards…

but there is the question as to what type of plug you should get and unwrapping your new shiny Taycan Turbo S and having the wrong plug type in your garage is a bit like unwrapping XMAS presents that require AA batteries and having none in the house and the stores are all closed…

and all this is a bit daunting and most people really don’t know how this whole AC power thing works - so add some complexity, some legacy infrastructure, some arcane building codes, some novelty that EV’s are “new”, some fluid standards over the years (6-50 used to be the standard prior to 1986), and some inconsistent applications of the standards (how many existing 14-50 pulgs actually do not have the neutral wires up in violation of the building codes), and clueless sales people and dealers - and it leads to long drawn out discussions like this…

it’s all very very confusing, and the reasons for choosing one plug type over the other is unclear…and even worse doesn’t really matter -

for example if you _NEVER_ travel away from home - the plug type you chooses does not MATTER FUNCTIONALLY - since you’ll simply buy an EVSE that matches the plug type you have in your home and it will always “work”

the reason plug choice matters is if you plan to travel - now you have the complexity of “guessing” which plug type you’re going to encounter during your travels - and you don’t want to be stuck someplace staring at a 240V plug - but it’s the wrong “shape” and you can’t charge your Taycan with it sitting at 4% battery…

and while NEMA 14-50 is the most common - it is by no means universal - so enter the complexity of wanting to charge while away from home, but having no idea really what type of NEMA plug you’ll encounter in the wild…it’s simply mind boggling and given that most people have never dealt with this type of complexity in the past - it can be overwhelming…and the fact that few if any people selling EV’s actually know anything about this stuff - lots and lots of misinformation and confusion.

add in legacay building code requirements, and an inventory of homes anywhere from 2 to 200 years old with different building codes and building quality - and it’s a huge recipe for confusion and conflicting information…

so no harm no foul as we sort this stuff

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