Wall Connector install - Planning ahead

[eprosenx]

It’s my understanding that the Nema if I go that route as an addition needs a neutral in addition to the ground however the WC just needs the ground, no neutral correct (due to it being 240) correct?

Oh and I forgot to answer this:

You are correct that a NEMA 14-50 requires a neutral to be run, but while the UMC Gen 2 comes with a 14-50 adapter, it totally ignores the neutral. It is completely unused. I think Tesla just includes that since 14-50's are used for ranges and RV's and so there are a lot of them out there in the wild.

If you want to avoid the cost of the extra neutral wire and the conduit space (if running in conduit), then you can simply install a 6-50 and get the $35 Tesla adapter for the UMC to allow you to use that. Frankly the neutral in the 14-50 is a waste for EV charging.

 

[eprosenx]

Now that I look at it, there were 4 unused breakers post solar install. You can see three of them remaining unused and turned off in the pic. Those used to be at the bottom, along with the space the solar sub panel eventually used.

Is there a fourth spare breaker that is just not in the off position right now? Or did you add a circuit that used up one of the four spares? I ask, as it could impact how you consolidate breakers to make room for an additional breaker for the HPWC/subpanel.

 

[Skione65]

@eprosenx,

True...the non-fused disconnect is more money initially than the fused (@$112), however the fused is just the box (@$86, then you need the 2 100A fuses at $19 each so your then up to $124 on the fused), so roughly the same.
I have decided to just used the non-fused due to simplicity and not having to deal with the fuses. Less to go wrong, less to trouble shoot though I did like the idea of redundancy and added protection but not at the cost of complexity.
Now to decide whether I want to run the additional wire in the conduit for the Nema as a redundant backup (I’ll probably never use but nice to have).

Ski

 

[GSP]

My wall connector has arrived in anticipation of my Model 3. I have a friend who is an electrician providing some advice when getting quotes for the install. He states the difference in material cost is minor for higher amperage circuits and planning ahead on the circuit size is a good idea. He isn't familiar with the details on how multiple WC's work, however.

The Model 3 LR will charge at a max of 48 amps which would require a 60a circuit. There's a good probability we'll end up with a second Tesla at some point and utilizing two wall connectors with the communication link would be ideal. With this in mind, would it be logical to install an 100a charging circuit now to the single WC? Clearly, a single wall connector would use roughly half of that, but adding a second connector in the future would avoid redoing the original install to handle the higher current.

Short of the higher gauge wire, different breaker, and an external power switch to the circuit, the cost of the labor would be similar.

Am I approaching this the right way? Those that have installed second Wall Connectors, did you have to redo the original install or did you run a totally different circuit to the 2nd WC?

I don't want to overdo a straightforward install, but I don't want to pay again to upgrade the first connector's install... assuming I'm understanding this all correctly.

Having a 100 Amp circuit to feed one or two HPWCs is not necessary for most people. However, it can be "nice to have" now and then for quick charging from a daily 70-80% to 90-100% just prior to a long trip. So, if 100 Amp is not much more expensive than 40-60 Amps for your home, then I would go for it.

However, what determines how fast your car needs to charge to meet your needs is not the car battery size or charging capabilities. Instead, it is your daily driving pattern(s). As long as you can charge overnight your typical daily miles used, faster charging will not be needed. Most people will be fine with a 20 or 30 Amp 240 V circuit.

My wife and I typically drive 10-20 miles per day, sometimes driving as much as 60-80 miles per day. Our two Teslas are both on 20 A 240 V circuits, and never have needed anything faster. No matter how much local driving we do, they are always "full" in the morning (they charge to 70% unless we are leaving for a road trip the next day). Only when we return from a road trip "near empty" (20-30%) will the car not be fully charged. That is no issue though, as the car still has more charge than needed for the day. It will catch up the next night and be fully charged.

So if you can easly do 100 A, go for it. If 100 A is expensive for your home's situation, then review your daily driving mileage and install fast enough charging to accommodate that.

GSP

 

[Rocky_H]

However, what determines how fast your car needs to charge to meet your needs is not the car battery size or charging capabilities. Instead, it is your daily driving pattern(s). As long as you can charge overnight your typical daily miles used, faster charging will not be needed. Most people will be fine with a 20 or 30 Amp 240 V circuit.

Thank you for mentioning this. A 60A circuit would still generally be enough even shared across two cars.

 

[NathanielHrnblwr]

Having a 100 Amp circuit to feed one or two HPWCs is not necessary for most people. However, it can be "nice to have" now and then for quick charging from a daily 70-80% to 90-100% just prior to a long trip. So, if 100 Amp is not much more expensive than 40-60 Amps for your home, then I would go for it.

However, what determines how fast your car needs to charge to meet your needs is not the car battery size or charging capabilities. Instead, it is your daily driving pattern(s). As long as you can charge overnight your typical daily miles used, faster charging will not be needed. Most people will be fine with a 20 or 30 Amp 240 V circuit.

My wife and I typically drive 10-20 miles per day, sometimes driving as much as 60-80 miles per day. Our two Teslas are both on 20 A 240 V circuits, and never have needed anything faster. No matter how much local driving we do, they are always "full" in the morning (they charge to 70% unless we are leaving for a road trip the next day). Only when we return from a road trip "near empty" (20-30%) will the car not be fully charged. That is no issue though, as the car still has more charge than needed for the day. It will catch up the next night and be fully charged.

So if you can easly do 100 A, go for it. If 100 A is expensive for your home's situation, then review your daily driving mileage and install fast enough charging to accommodate that.

GSP

Thank you for making that point as it wasn’t thinking about it that way. I need to research the charge rates a bit more. Minimum commute is 60mi round trip excluding any other driving. I have an 8 hour window to charge the car (TOU pricing) and a 20 amp circuit would be sufficient.

Assuming a second Tesla was added and a 60a circuit installed, there’s enough time to charge 260mi of range between the two.

A 60amp circuit would save me the disconnect hardware taking up room on the wall.

 

[Runt8]

Thank you for making that point as it wasn’t thinking about it that way. I need to research the charge rates a bit more. Minimum commute is 60mi round trip excluding any other driving. I have an 8 hour window to charge the car (TOU pricing) and a 20 amp circuit would be sufficient.

Assuming a second Tesla was added and a 60a circuit installed, there’s enough time to charge 260mi of range between the two.

A 60amp circuit would save me the disconnect hardware taking up room on the wall.

Not to mention that the wall connectors can share a 60a circuit just as easily as a 100a one (in fact the sharing feature probably makes more sense on lower amperage circuits). If you have two vehicles charging at the same time they each get 30a, which as @GSP mentioned can be plenty for normal driving.

 

[davewill]

...
A 60amp circuit would save me the disconnect hardware taking up room on the wall.

Of course, the disconnect box is also a handy place to to split the circuit for the two wall connectors. Plus, if you ever need to open them up for some reason, it's nice to have a disconnect in plain sight.

 

[Big Dog]

Wall Chargers can talk to each other, so unless you have to charge both cars at exactly the same time, a 60amp circuit should work.

 

[eprosenx]

Not to mention that the wall connectors can share a 60a circuit just as easily as a 100a one (in fact the sharing feature probably makes more sense on lower amperage circuits). If you have two vehicles charging at the same time they each get 30a, which as @GSP mentioned can be plenty for normal driving.

FWIW, really this means with two vehicles charging they each get 24 amps (a 60a circuit is only good for 48 amps continuous, so half that is 24). Oh, and I am not sure, but I think others have said that if you have a car plugged in but not charging, it still takes like a minimum of 6 amps away from what the other car can charge at right? Regardless, as others state, a 60a circuit shared between two cars is probably plenty for most folks driving patterns. How many days do you exhaust the full range of both cars and then also need full range again the next day? You can also charge outside of TOU optimal rates if you know you are desperate. A few extra bucks once in a blue moon might make it worth it...

Though on the flip side, you may use these EV chargers for many years (decades?). The wiring itself could be a multiple decade capital asset (in which case the amortized cost is tiny).

Wall Chargers can talk to each other, so unless you have to charge both cars at exactly the same time, a 60amp circuit should work.

And to be clear, you can charge both cars at exactly the same time, but neither will get full rate. If you need one to charge in a hurry you can just stop charging or disconnect the other one (or maybe crank it's charge rate down really low manually? - I don't know how the Wall Connector sharing would respond to that?)

 

[TheLocNar]

Got my 2nd estimate today. First guy was an independent. Guy today was from a local company that is Tesla’s top recommended in the area. He simply knew more, having done at least 1,000 wall connector installs over the years. 4AWG wire in conduit, a sub panel/shut off, 60A breaker in main panel etc. Run is about 35+ feet or so from basement (false ceiling) into garage. Village permits required as they send photos to Tesla. Price in estimate is cost of job. Any “surprises” and they eat it.

First estimate wants to use 6AWG and no sub panel/shut off. 50A breaker in estimate but we agreed on 60A. Typo/oversight. Village permit “up to you”. $1200.

Guess who I’m leaning towards at this moment. Heh.

3rd and final estimate Wednesday. Just ordered the 24’ wall connector tonight.

 

[eprosenx]

Got my 2nd estimate today. First guy was an independent. Guy today was from a local company that is Tesla’s top recommended in the area. He simply knew more, having done at least 1,000 wall connector installs over the years. 4AWG wire in conduit, a sub panel/shut off, 60A breaker in main panel etc. Run is about 35+ feet or so from basement (false ceiling) into garage. Village permits required as they send photos to Tesla. Price in estimate is cost of job. Any “surprises” and they eat it.

First estimate wants to use 6AWG and no sub panel/shut off. 50A breaker in estimate but we agreed on 60A. Typo/oversight. Village permit “up to you”. $1200.

Guess who I’m leaning towards at this moment. Heh.

3rd and final estimate Wednesday. Just ordered the 24’ wall connector tonight.

Wow, 4awg copper in conduit is good up to 85 amps. Are you saying they would only feed that subpanel with a 60a breaker? And then 60a breaker out of the subpanel to the HPWC as well? Seems overkill. Unless perhaps they would do a 80 amp breaker to the subpanel in the main panel and then a lower amperage breaker out to the HPWC? #6awg in conduit is good to 65 amps FWIW...

What was the estimate out of curiosity?

 

[TheLocNar]

Don’t have the 2nd estimate yet. Another day or two. Not sure about the nitty gritty details yet but I’ll update. A friend used the 2nd guys for their connector install and they actually came out costing less than the other estimates they got. If I can get 4AWG, why not. We will see!

 

[eprosenx]

Don’t have the 2nd estimate yet. Another day or two. Not sure about the nitty gritty details yet but I’ll update. A friend used the 2nd guys for their connector install and they actually came out costing less than the other estimates they got. If I can get 4AWG, why not. We will see!

Oh yeah, nothing wrong with 4awg! If that is the case, I might crank up the wall connector settings higher if the branch circuit (including breaker) was rated for it (an if you had enough capacity in the service per the NEC calculations).

 

[eladts]

Put the 100a breaker with #2,or #3 wire , dial down the amps in the WC to 48a ..in the future u can add second WC and set for load sharing

There is no need to dial down the HPWC to 48A. With a 100A breaker and properly sized wires, the HPWC should be set for 80A. The Model 3 won't be able to use it all, but it wall just pull what it can.

 

[davewill]

Any time someone suggests not doing a permit, you can bounce their butt immediately.

 

[TheLocNar]

Wow, 4awg copper in conduit is good up to 85 amps. Are you saying they would only feed that subpanel with a 60a breaker? And then 60a breaker out of the subpanel to the HPWC as well? Seems overkill. Unless perhaps they would do a 80 amp breaker to the subpanel in the main panel and then a lower amperage breaker out to the HPWC? #6awg in conduit is good to 65 amps FWIW...

What was the estimate out of curiosity?

First estimate is 1200 for 6AWG/60A breaker and no disconnect.

Second is 1350 for 4AWG and 2 60A breakers and disconnect panel. (Room to upgrade later if needed)

Third electrician coming tomorrow but so far, looks like I’ll be going with #2.

 

[voip-ninja]

First estimate is 1200 for 6AWG/60A breaker and no disconnect.

Second is 1350 for 4AWG and 2 60A breakers and disconnect panel. (Room to upgrade later if needed)

Third electrician coming tomorrow but so far, looks like I’ll be going with #2.

There is no need to run copper from the main panel to the disconnect panel. Aluminum is quite a bit less expensive.

I had an electrician run 75’ of 0/1 aluminum from my main panel on a new 100 amp breaker. He had to do a new conduit entry into the house but conduit was not needed for the rest of the run since he used SER cable.

He wired it into a new 125A sub panel that I provided and installed.

It was $700.

I then needed a $15 50 amp breaker and about $100 for 30 feet of 6/3 NMB to complete the run into my garage which I did on my own.

Splitting the job, pulling permits as a homeowner and doing the easier part of the job myself probably saved me about $300 over having the entire job done by an electrician.

 

[eprosenx]

Got my 2nd estimate today. First guy was an independent. Guy today was from a local company that is Tesla’s top recommended in the area. He simply knew more, having done at least 1,000 wall connector installs over the years. 4AWG wire in conduit, a sub panel/shut off, 60A breaker in main panel etc. Run is about 35+ feet or so from basement (false ceiling) into garage. Village permits required as they send photos to Tesla. Price in estimate is cost of job. Any “surprises” and they eat it.

First estimate wants to use 6AWG and no sub panel/shut off. 50A breaker in estimate but we agreed on 60A. Typo/oversight. Village permit “up to you”. $1200.

Guess who I’m leaning towards at this moment. Heh.

3rd and final estimate Wednesday. Just ordered the 24’ wall connector tonight.

You know, I just realized that maybe the reason for the 4 awg to the subpanel is because the electrician is planning to use aluminum wire? (that would be totally legit, just requires larger conduit if run in conduit due to the larger wire size). #4 aluminum is good to 65 amps. Note that the wire into the HPWC MUST always be copper though. So could use #6 copper for that.

 

[TheLocNar]

You know, I just realized that maybe the reason for the 4 awg to the subpanel is because the electrician is planning to use aluminum wire? (that would be totally legit, just requires larger conduit if run in conduit due to the larger wire size). #4 aluminum is good to 65 amps. Note that the wire into the HPWC MUST always be copper though. So could use #6 copper for that.

All copper as stated in proposal. I’m fine with it. Could upgrade in the future.

The 2nd quote is from the #1 rated Tesla installer in my area. Once I told him what car, he immediately knew “60A breaker to charge at 48A”.

First guy thought the M3 had the same specs as the S.

We will see what #3 brings to the table tomorrow.