Replacing 14-50 with HPWC, outlet on the wrong side of the stud

[brkaus]

Unless you want to make the UMC portable and carry with you for a trip, I don't see the advantage to have a plug.
I would recommend instead to install a safety switch next to the UMC.

Here is the extract of some recommendations from PG&E: CODE REQUIREMENTS FOR INSTALLING EVSE

Safety Switch: For EVSE rated at more than 60 amps or more than 150 volts to ground,
a means of disconnect must be installed in a readily accessible location and within sight of the electric charging connector.
If the disconnect is not in sight of the equipment, it must be capable of being locked in the open position (CEC §625.23).
Depending on local code requirements, a fused switch may be needed if the switch is not readily accessible,
or is not visible from the main panel.​

Just to be clear, a safety switch is only required if more than 60a on an HPWC. Each leg of the 240v circuit is less than 150v to ground.

But, If 60a or less, it is very cheap to add an air conditioning style blade disconnect switch.

What type/brand is the switch in the photo? It looks nicer than most I have found.

 

[Sophias_dad]

I'd tear off a chunk of drywall and screw some 2x4's or 2x3's between the studs which would allow you place it anywhere in that bay.

I used the center-bottom-rear screw-out(not really a knockout) for my HPWC. The small off-center one is for the signal connector only. You'll never get 4 AWG through the small one, and it would have to take some positively scary bends if you tried.

I had almost exactly the same setup you do, and ended up cutting out a chunk of drywall about 4x5", and inserted a chunk of 2x3 or somesuch to form the backer of the right hand row of holes on the backing plate. The left hand row was right on the stud.

 

[Glamisduner]

Just to be clear, a safety switch is only required if more than 60a on an HPWC. Each leg of the 240v circuit is less than 150v to ground.

But, If 60a or less, it is very cheap to add an air conditioning style blade disconnect switch.

What type/brand is the switch in the photo? It looks nicer than most I have found.

To keep it simple I plan to use a 60 amp breaker since the max the 3 can charge at is 48 amps. I'll worry about going higher if I get a second vehicle and HPWC or change vehicles later.

 

[eprosenx]

The HPWC was not tested by the NRTL with a plug, otherwise I would agree with you that you cannot modify the equipment without violating its listing. In this case, installing a cord and plug is allowed under under Art 400.7 and not specifically identified in 400.8 under "Uses Not Permitted", and finally, would be allowed under the provisions of EVSE's in Art 625.17(A) [All references to 2014 NEC]. I do not have a 2017 Code book, so it is possible there are other requirements and/or restrictions.

My version of the HPWC installation manual specifically identifies cord and plug installations in their troubleshooting section on page 22: "If the Wall Connector is plugged into a wall outlet, make sure that it is fully inserted into the receptacle...."

And yes, the cord and plug solution would be limited to 40 amps continuous charging but isn't the receptacle a 50 amp receptacle (and thus a 50 amp breaker anyway)? I agree wholeheartedly that if the building load calcs allow this branch circuit to make use of the full ampacity of the #4 conductor, that would be a faster charge and a great solution, but I haven't seen any answers to what kind of wiring it is or how long the branch circuit is. Maybe it was installed with #4 conductors for a reason, such as voltage drop or other required de-rating.

I suspect something changed between the 2014 code and the 2017 code. You can access the 2017 code on the NFPA web site for free now as long as you register (just FYI). I do not find a section 400.7 or 400.8. There is 400.10 (uses permitted) and 400.12 (uses not permitted) that sound similar. (Thank you for bringing article 400 to my attention! - I had not read it before)

My reading of the below does NOT indicate that you would be allowed to put a pigtail on a Wall Connector. I believe other EVSE's that come with a cord also come with quick release mounting brackets to allow 400.10(8) to be leveraged.

To the comment about the manual talking about a Wall Outlet plugged into a wall outlet: Great catch to notice that! (I have read the manual many times but never looked at the troubleshooting section) So here is my theory: They at one time made a Wall Connector that had a factory pigtail. Some of them apparently "leaked" into the open market. I get the idea they never were supposed to. I have talked with Tesla about this and they actually are trying to recover them (if you have one, I Tesla told me they would swap them out for a hardwired one for free).

I should also call out that article 625 changed a lot in the 2017 code. It very clearly does not allow a cord longer than 12 inches. I also can't find a reading that allows a cord whatsoever on the Wall Connector since the Wall Connector is very clearly "Fixed Equipment". It is not "Portable Equipment" or "Stationary Equipment".

Unless you want to make the UMC portable and carry with you for a trip, I don't see the advantage to have a plug.
I would recommend instead to install a safety switch next to the UMC.

Here is the extract of some recommendations from PG&E: CODE REQUIREMENTS FOR INSTALLING EVSE

Safety Switch: For EVSE rated at more than 60 amps or more than 150 volts to ground,
a means of disconnect must be installed in a readily accessible location and within sight of the electric charging connector.
If the disconnect is not in sight of the equipment, it must be capable of being locked in the open position (CEC §625.23).
Depending on local code requirements, a fused switch may be needed if the switch is not readily accessible,
or is not visible from the main panel.​

I totally agree that installing a pigtail (plug) on a Wall Connector is not a good idea for multiple reasons. For one it limits you to 40amps continuous, but more importantly, it also adds points of failure (and unlike the UMC, you would not have a temperature sensor at the plug end where it goes into the receptacle).

I disagree however about the need for a Safety Switch. I can't really conceive of a use for it and it is ugly and costly for a benefit that is hard to perceive. Here is exactly what 2017 NEC says:

So to parrot what others have said: You are NOT required to have a disconnecting means unless your installation is above 150 volts to ground (which neither 208/120v commercial systems nor 240/120v residential systems trigger), OR you have a *greater* than 60 amp circuit. Most Model 3 owners just install a 60a circuit (or less) so that does not even fall under this.

Even if you do fall under this requirement, the code does NOT specify it must be close to the EVSE or even within line of sight. It just be lockable in the open position. From everything I have read, this requirement can be accomplished with a small piece of stamped metal that fits over the circuit breaker itself which allows you to lock out the breaker in the off position. So it is like a few bucks for the metal and you are covered even if your breaker is in a different room.

I understand why Air Conditioning equipment requires a local disconnect (since you have maintenance tech's working on them all the time), but EVSE's are really not serviceable so I don't really see the point. I also don't really understand why they distinguish between something over 60a and under 60a... A 50a circuit likely can kill you just as easily as a 70a one? I guess the difference being the available fault current?

FWIW I have my Wall Connector installed outside my garage with no disconnect. I don't even have the breaker panel lock out device since it is only on a 60a circuit. I have zero safety concerns and I am pleased with the aesthetics of the install. I really can't think of a safety scenario where I would need a local disconnect (other than my car battery being on fire - at which point the 8' or 24' cord is not far enough for me to be able to safely hit the disconnect - once a Tesla catches on fire turning off the shore power is not going to help)

(we have discussed both the "install a cord on the Wall Connector" option as well as the "safety disconnect" device options multiple times on the forums so if you want more gory details on either I would recommend searching a bit before re-hashing it here)

 

[Glamisduner]

I still have not figured this out yet. I went to the hardware store and bought just about every 1" adapter thing they had.I bought a blank box cover so I can drill my own hole (they didn't sell covers with 1 inch holes). The issue is, the wall connector flush-mount rear entry is threaded, so my adapters thread into it fine. But then how the heck and I thread an adapter into the box too?

It's a real bummer they made this so hard to install

I'm tempted to just put a box cover, then use a wire clamp exit and feed the wires into the HPWC. Like this one
1 in. Non-Metallic (NM) Twin-Screw Clamp Connector-90513 - The Home Depot

But I believe these are supposed to be used for romex and not THHN. I really do not see another way to go from an electric box into the back side of the HPWC though.

I think the only way to properly attach the HPWC using the rear 1" threaded hole is to run 1" metal conduit directly to the back of the wall charger, then use a compression fitting or similar to attach the HPWC to the conduit. This seems crazy to me, since that would require the metal conduit to be installed in the wall? Am I missing something? I have scoured the web for videos of how to install HPWC using the rear entry, but they go from installing a fitting in the back to it hung on the wall, they never how how they ran the wire through the rear of it .

 

[eprosenx]

I still have not figured this out yet. I went to the hardware store and bought just about every 1" adapter thing they had.I bought a blank box cover so I can drill my own hole (they didn't sell covers with 1 inch holes). The issue is, the wall connector flush-mount rear entry is threaded, so my adapters thread into it fine. But then how the heck and I thread an adapter into the box too?

It's a real bummer they made this so hard to install

I'm tempted to just put a box cover, then use a wire clamp exit and feed the wires into the HPWC. Like this one
1 in. Non-Metallic (NM) Twin-Screw Clamp Connector-90513 - The Home Depot

But I believe these are supposed to be used for romex and not THHN. I really do not see another way to go from an electric box into the back side of the HPWC though.

I think the only way to properly attach the HPWC using the rear 1" threaded hole is to run 1" metal conduit directly to the back of the wall charger, then use a compression fitting or similar to attach the HPWC to the conduit. This seems crazy to me, since that would require the metal conduit to be installed in the wall? Am I missing something? I have scoured the web for videos of how to install HPWC using the rear entry, but they go from installing a fitting in the back to it hung on the wall, they never how how they ran the wire through the rear of it .

So the hack job in me would be tempted to just screw the Wall Connector directly over the electrical box and run the wires in without any adapter.

The plastic threads of the Wall Connector are probably not sharp enough to be an issue for the wires. You are passing the wire from one protected space (the receptacle box) to another protected space (the Wall Connector wire bay). Once installed the wires will never move.

Now my “non hack job” answer is the following:

Mount the Wall Connector to the next stud over. Run 1 inch LFMC or LFNC from the bottom of the Wall Connector to a 90 degree adapter that goes into a cover plate with a 1” knockout. They may not sell them with a 1 in knockout so you may need to drill it (or really the right way is to “punch” it) yourself.

This solution is simple and easy. I bought a set of punches recently at Harbor Freight for my wall connector project so I could make a bigger knockout in my electrical panel.

 

[Glamisduner]

So the hack job in me would be tempted to just screw the Wall Connector directly over the electrical box and run the wires in without any adapter.

The plastic threads of the Wall Connector are probably not sharp enough to be an issue for the wires. You are passing the wire from one protected space (the receptacle box) to another protected space (the Wall Connector wire bay). Once installed the wires will never move.

Now my “non hack job” answer is the following:

Mount the Wall Connector to the next stud over. Run 1 inch LFMC or LFNC from the bottom of the Wall Connector to a 90 degree adapter that goes into a cover plate with a 1” knockout. They may not sell them with a 1 in knockout so you may need to drill it (or really the right way is to “punch” it) yourself.

This solution is simple and easy. I bought a set of punches recently at Harbor Freight for my wall connector project so I could make a bigger knockout in my electrical panel.

So your suggesting I don't use the rear flush mount plate and instead use the plastic adapter to I can run conduit out the bottom (instead of the back?) I was wanting to cover up 14-50, but this would work. however the next stud over will either place it above my workbench or behind my drill press But I imagine I could mount it to the same stud using and just use two 90s. I'm just not sure how much length of wire will be in the box, there may be enough though if I put it on the same stud. The piece of flex conduit would only be maybe 4"?

 

[Needsdecaf]

You could hit the stud with the two holes on the left side of the bracket. Those alone would pretty stout, but you should probably add sheetrock anchors on the right side. Another option would be to span the two studs with thick plywood or two short 2x4's and then screw the bracket to the wood.

This.

Drywall is easy and cheap to fix. Rip open and block in a backing for the outlet, then repair.

 

[Glamisduner]

This.

Drywall is easy and cheap to fix. Rip open and block in a backing for the outlet, then repair.

Yea the hard part is figuring out where put the support, which is determined on where the HPWC will be installed, which is determined by how I can get the wires to the HPWC. Which is what I'm still stuck on. I guess I should give up on the flush mount and use the plastic backing plate and the hole on the bottom.

 

[SMAlset]

I wanted a clean look and run the wiring needed inside the wall instead of along the wall when we installed our NEMA 14-50 so our electrican ended up having to cut our drywall and added a short support beam where he needed for support. Put the drywall back and taped and mudded. We needed to have the cutout closed up to meet code.

 

[Glamisduner]

I wanted a clean look and run the wiring needed inside the wall instead of along the wall when we installed our NEMA 14-50 so our electrican ended up having to cut our drywall and added a short support beam where he needed for support. Put the drywall back and taped and mudded. We needed to have the cutout closed up to meet code.

I will assume this was for romex and not THHN wires? Or basically you didn't need to run the wire in conduit into the back of the HPWC? Right now I'm thinking about just using some flex conduit into the bottom because that seems easy, but it won't give me as clean of a look, and I would need to replace the drywall to get rid of the cutout for the box (but I don't think it's a code issue as the wire would be completely enclosed by the box and conduit)

 

[eprosenx]

So your suggesting I don't use the rear flush mount plate and instead use the plastic adapter to I can run conduit out the bottom (instead of the back?) I was wanting to cover up 14-50, but this would work. however the next stud over will either place it above my workbench or behind my drill press But I imagine I could mount it to the same stud using and just use two 90s. I'm just not sure how much length of wire will be in the box, there may be enough though if I put it on the same stud. The piece of flex conduit would only be maybe 4"?

FYI, I was proposing you extend the wires using that existing box as a junction box. I have seen wire nuts for 6awg, but bigger than that you probably need Polaris connectors (maybe not even a bad idea for 6 awg).

 

[Glamisduner]

FYI, I was proposing you extend the wires using that existing box as a junction box. I have seen wire nuts for 6awg, but bigger than that you probably need Polaris connectors (maybe not even a bad idea for 6 awg).

Ahh ok, I think they electrician left extra wire in another junction box. I don't have any time to work on this for a couple weeks, and I have a dryer outlet I can use while figuring things out. I think the bottom entry with conduit tin along the wall is going to be the easiest route.

 

[Sophias_dad]

Here's another solution which may or may not work...

Make a similar hole at the top of a blank cover plate, then use your twin screw clamp connector THROUGH that hole and into the rear-entry of the HPWC. There are two problems with this, though...

It'll be difficult to screw that blank cover plate onto its box since you've just attached an HPWC to it which is gonna cover two of its mounting holes.

You really aren't supposed to be using those twin screw clamp connectors with individual conductors.. They are intended for romex.


I'd probably just skip the clamp entirely.... Actually, I'd probably open the wall and remove the box completely, then use the 1" clamp to properly connect the wire to the HPWC.

 

[eprosenx]

Here's another solution which may or may not work...

Make a similar hole at the top of a blank cover plate, then use your twin screw clamp connector THROUGH that hole and into the rear-entry of the HPWC. There are two problems with this, though...

It'll be difficult to screw that blank cover plate onto its box since you've just attached an HPWC to it which is gonna cover two of its mounting holes.

You really aren't supposed to be using those twin screw clamp connectors with individual conductors.. They are intended for romex.


I'd probably just skip the clamp entirely.... Actually, I'd probably open the wall and remove the box completely, then use the 1" clamp to properly connect the wire to the HPWC.

I think the OP said they had conduit behind the sheetrock and not romex.

 

[Sophias_dad]

I think the OP said they had conduit behind the sheetrock and not romex.

Yep, now that I read the thread again, its 4AWG in conduit. I'm not sure about the rules on extending conduit(obviously you can't make connections in conduit!), but I would think you could still remove the box and feed the conduit into the back of the HPWC, assuming there's enough conductor length left.

 

[Glamisduner]

So I think I Need a 1x4 for the area that goes over the conduit (2x4 is too thick).

I'm still not sure how to get the conduit to go into the back of the wall connector? I'm thinking to just cap off the box and come back out the top of it. Or maybe even remove the box completely?

Also even if I can get a 1x mounted, the box will be in the way of the 2x4, and the mount isn't long enough. it looks like I will need to remove the electrical box?

 

[brkaus]

Can you mount the hpwc bracket on the stud to the right?

Then bring conduit out of the right side of the box and into the back. Put a plate on the box. You would have to use appropriate splice blocks.

 

[Sophias_dad]

I believe the right solution is to remove the box and put an elbow at the end of the conduit. I'm not sure if they make them, but if there's an elbow that direct connects(screws) into the back of the HPWC, all the better. ... here's one...Halex 3/4 in. EMT/Rigid Pull Elbow-94707 - The Home Depot

Note that I'm not sure of the size of the entry hole on the back of the HPWC.. Its either 3/4 or 1", I can't recall... Sadly, after a bit of research, it looks like 1", so you'll have to get an adapter or somesuch to get to the right size(if you don't already have 1" conduit). There are 1" versions of the above emt/rigid pull elbow.

It looks like you already are aware, but it isn't allowed to completely bury a box under drywall... it has to have access through the drywall, even if its just a blank cover.

 

[Sophias_dad]

It looks like you already are aware, but it isn't allowed to completely bury a box under drywall... it has to have access through the drywall, even if its just a blank cover.

On rereading this... I think the rule is that there are no connections made in a box that's inaccessible. If the wires just went through the box, it'd probably be acceptable to bury it. That said, if they are just going through the box, its better to just remove the box.