Tesla Wall Connector: Hard wiring Vs NEMA 14-50

[ajexpert]

I’ve my Tesla Model Y delivery date finalized and now I’m exploring the options for charging. I ordered Tesla Wall Connector and thinking to connect to NEMA 14-50 for flexibility. Appreciate if I get response to following questions.

• I understand that 60 Amp hard-wired wall connector works best, however, what are the cons of installing NEMA 14-50 with 50 Amp wire? Appreciate if someone let me know how slow the charging will be if Tesla Wall Connector is connected to NEMA 14-50 (50 Amp)
• Assuming I opt for NEMA 14-50, would it affect the installation rebate or any State/Federal(?) rebate? One electrician said if I do not opt for hard wiring, the rebate can be denied. Is it true?
• Any EV rebates available to apply for state of MD (Montgomery County)?

TIA

 

[240vPlug]

A properly installed 14/50 outlet is perfectly safe for EV charging, just as safe as a Wall charger. The fact that you keep mentioning that these are unsafe is proof that you should educate yourself before making these kinds of statements.

All 14-50 are not created equal. The contactors and the plug are two additional failure points which make a 14-50 based system more failure prone and therefore less safe than a hard wired setup. A 14-50 can certainly be safe for EV charging but it’s slower and not necessary for a permanent home charger install.

I have educated myself having owned plug in vehicles for the past 6 years and installing numerous chargers. Further I have seen many 14-50 plug and receptacles melt/burn and have yet to see a hard wired setup that’s installed to code suffer any such failure.

Anyone reading can reach their own conclusion. There is a reason why Tesla also recommends the same.

 

[TheLex]

I will add to this as someone who regularly travels with a big 50 amp fifth wheel, while the industrial 14-50 sockets are generally pretty robust at campgrounds, there's always the possibility of a short. That's why the electrical box has a breaker, and it's recommended that one use an electrical management surge protector between your fifth wheel's power cord and the breaker box. I have encountered bad 14-50 receptacles that caused my EMS to trip. I can't imagine what might happen to the Tesla should something like that happen.

 

[jcanoe]

The 50 amp GFCI breaker is $140 at my local big box hardware store. The Hubbell 14-50 is about $100. That's already $250. The Tesla Wall Connector is $400. Considering my experience with PITA GFCI breakers tripping in hot weather (on top of which my garage is not air conditioned) the TWC is a no brainer for me.

If you are installing a 50A charging circuit from scratch the cost of the current Tesla Mobile Connector kit ($200), quality 14-50 receptacle, plus GFCI circuit breaker is about the same as the cost of the Tesla Wall Connector ($400). If you already have the 14-50 receptacle installed you would only need the Tesla Mobile Connector kit ($200) and maybe the Cable Organizer ($35.) BTW if the local electrical code did not adopt the 2017 or 2020 revision of the code at the time the circuit was installed you are not required to change the breaker to a GFCI breaker. (For the same level of protection as the GFCI circuit breaker or receptacle when plugging or unplugging the equipment always first turn off the power at the breaker.)

 

[804son]

All 14-50 are not created equal. The contactors and the plug are two additional failure points which make a 14-50 based system more failure prone and therefore less safe than a hard wired setup. A 14-50 can certainly be safe for EV charging but it’s slower and not necessary for a permanent home charger install.

I have educated myself having owned plug in vehicles for the past 6 years and installing numerous chargers. Further I have seen many 14-50 plug and receptacles melt/burn and have yet to see a hard wired setup that’s installed to code suffer any such failure.

Anyone reading can reach their own conclusion. There is a reason why Tesla also recommends the same.

If additional contact points are an indication of potential failure, your theory has some problems

 

[Sophias_dad]

If additional contact points are an indication of potential failure, your theory has some problems
View attachment 852681

You have a 'point' there. The Gen3 HPWC has three sliding spade connectors that connect the backplate to the guts of the unit. That said, its unlikely an HPWC will get the guts removed from the backplate more than ten times in its life, which is something you can't possibly say(but can hope for) with a 14-50 outlet.

 

[240vPlug]

I will add to this as someone who regularly travels with a big 50 amp fifth wheel, while the industrial 14-50 sockets are generally pretty robust at campgrounds, there's always the possibility of a short. That's why the electrical box has a breaker, and it's recommended that one use an electrical management surge protector between your fifth wheel's power cord and the breaker box. I have encountered bad 14-50 receptacles that caused my EMS to trip. I can't imagine what might happen to the Tesla should something like that happen.

Excellent point. I have one of those as well. Also easier to reset if the breaker trips in the middle of the night

If additional contact points are an indication of potential failure, your theory has some problems
View attachment 852681

and adding a 14-50 will reduce the number of contact points? From what I see it increases it and further supports my argument. Now your grasping at straws my friend.

There is no good arguement for using a 14-50 over a hard wired setup. Even if you have an existing 14-50 that should only be a temporary solution.

By all means if after reading this you still want to use a 14-50 go ahead. I know I am more comfortable charging 18% faster and having no concerns about melting plugs and receptacles in the middle of the night (when many folks charge).

If it’s helpful all the times I have seen the melting a burning it never burned down the property. It mainly just damaged the immediate area around the 14-50. If your installing a TWC though putting it on a 14-50 will not pass a code inspection.

 

[ajexpert]

Just to reiterate, there is no 14-50 option with the Tesla Wall Connector that 100% adheres to code. It is not designed for this, or permitted in the installation manual for this. You have to hardwire the wall connector, and that would be clear when the electrician opens up the unit anyways. They would essentially be retrofitting a cord.

"It is literally a violation of electric code. Code has kind of a blanket catch-all that you need to connect an appliance according to its manufacturer's instructions. It is built to be a hard wired device, and does not have the proper lugs that are made for the fine stranded wire that those external cord and plugs usually have."

There's no good reason to go 14-50 with this device since you can easily remove it and put a 14-50 in its place down the road if you ever needed to. But I'm not sure why you would - a Tesla to J1772 adapter can adapt the Tesla Wall Connector to be used on any electric vehicle.

Thanks @fiehlsport. If connecting TWC to NMEA 14-50 is violation of electric code, I think the county inspector will not approve the permit. Is my understanding correct?

 

[240vPlug]

Thanks @fiehlsport. If connecting TWC to NMEA 14-50 is violation of electric code, I think the county inspector will not approve the permit. Is my understanding correct?

It should be caught when you submit for the permit and they should require a resubmission. Then they should inspect it afterwards to make sure it was done properly.

My understanding is that this is the reason manufacturers make two different versions of the same charger (one corded and one hard wired). They can of course only do that if it’s limited to 40amps or less. If the charger is capable of >40 amps it needs hard wired.

 

[ajexpert]

Excellent point. I have one of those as well. Also easier to reset if the breaker trips in the middle of the night

and adding a 14-50 will reduce the number of contact points? From what I see it increases it and further supports my argument. Now your grasping at straws my friend.

There is no good arguement for using a 14-50 over a hard wired setup. Even if you have an existing 14-50 that should only be a temporary solution.

By all means if after reading this you still want to use a 14-50 go ahead. I know I am more comfortable charging 18% faster and having no concerns about melting plugs and receptacles in the middle of the night (when many folks charge).

If it’s helpful all the times I have seen the melting a burning it never burned down the property. It mainly just damaged the immediate area around the 14-50. If your installing a TWC though putting it on a 14-50 will not pass a code inspection.

Thanks 240vPlug. Yeah, I'm ok to charge at slower speed using NEMA-1450. Also, the quote I got from electrician is same price to either hardwire TWC OR install 50 A with GFCI Breaker and NEMA 14-50 receptacle.

I want to go for generic and safe solution assuming I buy another non-Tesla EV in next couple of years or move out. If I buy the industrial grade NEMA 14-50 and install would it still be unsafe or code violation?

 

[ajexpert]

It should be caught when you submit for the permit and they should require a resubmission. Then they should inspect it afterwards to make sure it was done properly.

My understanding is that this is the reason manufacturers make two different versions of the same charger (one corded and one hard wired).

Thanks again 240vPlug. I believe we have only one version of TWC available now which allows to be hard wired and connect to receptacle. Please correct me if I'm wrong.

 

[240vPlug]

Thanks again 240vPlug. I believe we have only one version of TWC available now which allows to be hard wired and connect to receptacle. Please correct me if I'm wrong.

Your right, at this time I am not aware of a TWC that ships with the 14-50. Tesla would have to make a 2nd version of the charger and have a hard limit of 40amps in order to be able to sell it with a 14-50. Because it can go up to 48 amps its only available in hard wired (no receptacles).

TWC can be used with other EV using a Tesla to J1772 adapter. One popular brand is lectron. Just make sure you get one with the appropriate amperage rating (you need at least 48 amps). My wife has a Rivian R1S and we plan to use the TWC to charge it with the adapter. This is because we can share the 60 amp circuit between the two TWC using WiFi which is a feature I really like about the TWC.

If you want to future proof against a non Tesla EV just get a hard wired EVSE from ChargePoint or similar and use the OE supplied J1772 to Tesla adapter to charge.

If you insist on a 14-50 you should go with a charger that shipped corded for a 14-50.

The reason why I am so passionate about EVSE installs is because they can be a serious safety issue if not installed properly. Also code violations could cause problems with a home sale or insurance claim.

 

[fiehlsport]

If you get another non-Tesla EV in the future just get this:

Lectron Tesla to J1772 EV Adapter | 250V | 48 Amp

Lectron Tesla to J1772 Charging Adapter 48A. Compatible with Tesla High Power Wall Connector, Destination Charger, and Mobile Connector.

ev-lectron.com

We use it every day to charge our Hyundai Ioniq, and it clips into a J1772 holster on the wall so there's no inconvenience of taking the adapter on and off.

Hardwire your wall connector, run it at 48A, and have confidence it will be safe and installed correctly. The Tesla EVSE is the best vehicle charger you can get right now for pretty much any price, there is no need to get something else with a 14-50 down the road.

 

[Sophias_dad]

Also, the quote I got from electrician is same price to either hardwire TWC OR install 50 A with GFCI Breaker and NEMA 14-50 receptacle.

That is pretty sketchy. Unless the electrician is overcharging by an enormous amount, I can't imagine him not caring whether he installs another $200 in parts. I assume he's planning to save a little money on using smaller conductors(50A instead of 60A), but that won't be anything like $200.

 

[jcanoe]

Tesla does not currently sell a corded version of the Wall Connector. Tesla does currently sell a corded version of the Mobile Connector with a fixed 14-50 power plug. The Tesla Corded Mobile Connector enables charging at 40 amps. (The Corded Mobile Connector is usually Out of Stock.)

 

[stopcrazypp]

Thanks @fiehlsport. If connecting TWC to NMEA 14-50 is violation of electric code, I think the county inspector will not approve the permit. Is my understanding correct?

If you say that in the application, an inspector that looks at the details (including Tesla installation instructions) would not allow it, given it does not follow manufacturer instructions, which is a violation of 110.3(B):

110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

Is it safe to use 70 amp breakers for home wall connectors to charge Model 3?

If instead your permit application was just for a 14-50 outlet, and you get it passed before installing the TWC, the inspector might not know, but you would still be in violation (essentially your TWC was installed without permit and not following instructions). This can have consequences with your insurance if a fire happens.

There is also another issue, that there some local inspectors that do not recognize the software current limiting toggle of the Gen3 TWC as a valid limiter, so would require everything downstream to handle 60A (some people that wanted to install it on a 50A circuit have run into this problem). The Gen2 version and older used physical dip switches instead.

If you are dead set on a TWC, I would hardwire personally. It only makes sense to go with 14-50 if you are getting the mobile connector.

 

[Sun&moon]

I did something similar -- I had a 6-50 outlet that I was using with the mobile connector. I added a cord and 6-50 plug to the wall connector and plugged it in to the plug (making sure to turn the wall connector down to 40 amps). It has been working like this for over 2 years. I've checked the cord I added and it doesn't seem to get too hot to the touch after many hours of charging.

Am also planning to do the same am running a line for 6-50 that has two hot and one ground for a mobile connector. Later from that connection I can give the connection to wall connector. Am wondering why no one speaks about this cheap option but everyone is discussing about 14-50 the one comes with neutral whereas the wall connector doesn't need Neutral.

 

[stopcrazypp]

Am also planning to do the same am running a line for 6-50 that has two hot and one ground for a mobile connector. Later from that connection I can give the connection to wall connector. Am wondering why no one speaks about this cheap option but everyone is discussing about 14-50 the one comes with neutral whereas the wall connector doesn't need Neutral.

Actually this has been mentioned a lot, but the forum is huge so not easy to find. Here's a thread for example:
NEMA 14-50 vs 6-50
Most people go with a 14-50 because that is the most universal solution (most J1772 EVSEs also have 14-50 options, but 6-50 seems to be rare).

Here in Bay Area, electricians that pre-wire a garage for a EVSE installs a 14-50, I have never seen a 6-50.

 

[jcanoe]

Am also planning to do the same am running a line for 6-50 that has two hot and one ground for a mobile connector. Later from that connection I can give the connection to wall connector. Am wondering why no one speaks about this cheap option but everyone is discussing about 14-50 the one comes with neutral whereas the wall connector doesn't need Neutral.

If you are starting out, installing a new charging circuit then just install the Wall Connector. The money you save on not having to use a GFCI circuit breaker, Hubbell receptacle and box, etc. will more than offset the additional purchase price of the Wall Connector ($425 US) versus the Mobile Connector ($230 US). Most of the cost is in the installation, not much savings with running 2 wires versus 3 wires, plus ground wire. The GFCI breaker should not be used with the Wall Connector, you could later sell the GFCI used but that takes time. Why have an electrician come back to install the Wall Connector when this can be accomplished up front?

In the US the 6-50 is mostly used with welding equipment; the 6-50 is more common in Canada. In the US the 14-50 is commonly found at campgrounds for powering RVs, EV charging.

 

[240vPlug]

If you are starting out, installing a new charging circuit then just install the Wall Connector. The money you save on not having to use a GFCI circuit breaker, Hubbell receptacle and box, etc. will more than offset the additional purchase price of the Wall Connector ($425 US) versus the Mobile Connector ($230 US). Most of the cost is in the installation, not much savings with running 2 wires versus 3 wires, plus ground wire. The GFCI breaker should not be used with the Wall Connector, you could later sell the GFCI used but that takes time. Why have an electrician come back to install the Wall Connector when this can be accomplished up front?

In the US the 6-50 is mostly used with welding equipment; the 6-50 is more common in Canada. In the US the 14-50 is commonly found at campgrounds for powering RVs, EV charging.

Wall connector is also safer and can charge faster (48 amps vs 32). For a permanent home charging install a hard wired wall connector is the best solution. I have seen to many melted plugs and receptacle over the years. They are fine for occasional use or even frequent as a temporary but it's not a good long term solution to use the mobile connector.

Around here most new construction install wiring (no receptacle) for the EV charger. They advertise it as a "rough in for EV charger". These receptacle were never designed for the sustained continuous high load of EV charging. Eventually the contacts will wear out resulting in arcing, melting, burning, and possibly properly damage. Then there are the plugs mostly manufactured overseas with poor QC. Skip all that and hard wire the wall connector is my suggestion.

I am all for saving money and I think you will find the hard wired setup may actually be the same or less and provide the benefits and piece of mind mentioned above.

 

[Sun&moon]

If you are starting out, installing a new charging circuit then just install the Wall Connector. The money you save on not having to use a GFCI circuit breaker, Hubbell receptacle and box, etc. will more than offset the additional purchase price of the Wall Connector ($425 US) versus the Mobile Connector ($230 US). Most of the cost is in the installation, not much savings with running 2 wires versus 3 wires, plus ground wire. The GFCI breaker should not be used with the Wall Connector, you could later sell the GFCI used but that takes time. Why have an electrician come back to install the Wall Connector when this can be accomplished up front?

In the US the 6-50 is mostly used with welding equipment; the 6-50 is more common in Canada. In the US the 14-50 is commonly found at campgrounds for powering RVs, EV charging.

Thank you. Same am doing as you said.