Which home Wall Connector

[Ric Shaner]

Hello,

I am looking to have a wall connector installed in my garage. There are several options available both the Tesla brand and others. I am dead set on buying a Tesla M3, although not sure it it will be Standard or Long range. What I know about electricity, amps, volts and the like can fit on the head of a pin. I would like advice on whether or not to by the Tesla Wall Connector or another brand, if another brand which one. My Tesla will be mostly a daily driver.

Thank you,

Ric

 

[kpanda17]

Design to code or better and all will be good
I did all copper and all gauged down a number, meaning thicker, and performs amazingly
4 gauge for each of my 60s to WCs
1 gauge from the sub panel 65 feet to the main panel
125 amp feeding a subpanel with 2x 60 amp circuits and 2x 20s for misc
Runs flawlessly with two at 96amps, scheduled during the overnight time of use window

Btw, next time you are at a supercharging charging at 250kw, you will notice the cable is warm
Warm is not terrible
Hot is bad

 

[Eric33432]

A 60amp/240v circuit is likely to be the largest, single circuit, breaker in the OP's electrical panel. A typical home in North America has a 200amp/240v main breaker, so it's a bit more complicated than just installing the highest current possible breaker/EVSE to feed an EV. The OP admits to knowing little about volts and amps so he probably should state the various loads on his panel and it's main breaker amperage. He should have a load evaluation done by an electrician, as he could, potentially, be overloading his panel depending on the other high amperage/240v loads that it's feeding.

Our winter home in SE AZ has the following (IIRC) 240V breakers and loads:
40Amp/heat pump
50A/stove
40A/dryer
40A/HW Tank
20A/EVSE
190A
You can see that in our home a 60amp/240V EVSE would be pushing the 240v nominal loads, alone, to 230A. Of course we don't normally have all these loads maxed out and the breakers are ~20% oversized, but with 120v loads added in, we could potentially trip the main breaker if the EVSE was drawing 48A.

That is why I said OP should "install the largest circuit that he can install economically".

You don't add up all the breakers to see if a panel is overloaded. Rather you do a load study.

Every house I have done a load study for that had 200 amp service had no problem with a 60 amp (48 amp charging) EV circuit.

Here is one for your house. I assumed 3,000 square feet, and normal kitchen appliances and a few other things, and a 48 amp EV circuit. I also assumed 9,600 watts of backup heat for the heat pump that can run concurrently with the heat pump. Even if my assumptions are off, you would have no problem with a 60 amp circuit for 48 amp charging.

Download Mike Holt's Electrical Tool Box and run a load calculation yourself.

A. General Lighting/Receptacles:

Living Area in Sq. Ft.:

3000sq. ft.

Small Appliance Circuits: 2 Circuits

Laundry Circuit(s): 1 Circuit(s)

B. Fixed Appliances and Equipment:

Dishwasher(s), 120V:1Unit(s),15 Amperes

Disposal(s), 120V:1Unit(s),15 Amperes

Electric Vehicle Charger(s), 240V:1Unit(s),48 Amperes

Microwave(s), 120V:1Unit(s),1800 VA

Water Heater(s), 240V:1Unit(s),4500 VA

Electric Dryer(s), 240V:1Unit(s),5000 VA

Range (Cooktop/Oven)(s), 240V:1Unit(s),14000 VA

C. Cooling/Heating Load(s):

Cooling Load: AC/Condenser
25A and Fan 2A, 240V

Heating Load: Heat
9600 VA and Fan 2A, 240V

COPPER RESULTS​

1. Service Disconnect Rating: 175A
2. Service Conductor Size:
1/0 AWG, rated 150A at 75°C
3. Service Neutral Conductor Size: 6 AWG, rated 65A at 75°C
4. Supply-Side Bonding Jumper: 6 AWG
5. Raceway Size: 2 Inch

ALUMINUM RESULTS​

1. Service Disconnect Rating: 175A
2. Service Conductor Size: 3/0 AWGAL, rated 155A at 75°C
3. Service Neutral Conductor Size: 4 AWGAL, rated 65A at 75°C
4. Supply-Side Bonding Jumper: 4 AWGAL
5. Raceway Size: 2 Inch

Service Calculation[220.82(B)]

A. General Lighting/Receptacles:

Living Area: 3000 x 3 VA = 9000VA

Small Appliance Circuits: 1,500 VA x 2 = 3000VA

Laundry Circuit(s): 1,500 VA x 1 = 1500

B. Fixed Appliances and Equipment

Dishwasher(s), 120V:1Unit(s) x 15 Amperes x 120V =1800VA

Disposal(s), 120V:1Unit(s) x 15 Amperes x 120V =1800VA

Electric Vehicle Charger(s), 240V:1Unit(s) x 48 Amperes x 240V =11520VA

Microwave(s), 120V:1Unit(s) x 1800 VA = 1800 VA

Water Heater(s), 240V:1Unit(s) x 4500 VA = 4500 VA

Dryer(s), 240V:1Unit(s) 1Unit(s), x 5000VA = 5000 VA

Range (Cooktop/Oven)(s), 240V:1Unit(s), 14000VA

Subtotal: 53920VA
First 10,000 VA at 100%: 10000

Remainder 43920 VA at 40% = 17568 VA

Subtotal Demand Load: 27568 VA

C. Cooling/Heating Load(s) [220.82(C)]:

Cooling Load at 100%: 240V x (25A + 0 A) = 6480 VA


[Omit Per 220.60]

Heating Load at 65%: [9600VA +(240V x 2 A)] x 65% = 6552 VA

[Omit Per 220.60]

Cooling/Heating Demand Load: 13032 VA

Total Service Demand Load:

Service Demand VA Load (A, B, and C):40600 VA

Service Load in Amperes: 169A ( 40600 VA/240V)

NOTES:​

1. Service Disconnect Rating [240.4 and 240.6(A)]

Service disconnect sized must have an ampacity of at least 169A

Service Disconnect Rating: 175A

2. Service Conductor Size [310.15(B)(7) and Table 310.15(B)(16)]

Service conductor sized to 83% of 175A service disconnect rating.

175x 83% = 145.25A

3. Service Neutral Conductor Size [220.61 and Table 310.15(B)(16)]

A. General Lighting, Small Appliance, and Laundry VA Load: [220.42]

General Lighting: 3000 sq. ft. x 3 VA = 9000 VA

Small Appliance Circuits: 1,500 VA x 2 = 3000 VA

Laundry Circuit(s): 1,500 VA x 1 = 1500 VA

First 3,000 VA at 100% = 3000 VA

Remainder, 10500 VA at 35% = 3674.9999999999995 VA

General Lighting, Small Appliance, and Laundry Demand Load: 6675

B. Appliance(s) VA Load:​

Dishwasher(s), 120V:1Unit(s) x 15 Amperes

Total: 5400 VA x 75% = 4050 VA, 220.53

Disposal(s), 120V:1Unit(s) x 15 Amperes

Total: 5400 VA x 75% = 4050 VA, 220.53

Microwave(s), 120V:1Unit(s) x 1800 VA

Total: 5400 VA x 75% = 4050 VA, 220.53

C. Dryer(s) VA Load [220.60]​

Neutral Demand Load [220.61(B)]​

5000VA x 70% = 3500 VA, 220.54

D. Cooking Equipment VA Load [220.61] and Table 220.55​

Neutral Demand Load [220.61(B)]​

0 VA x 70% = 0 VA, 220.55

Neutral VA Demand Load(A, B, C, and D)​

6675 VA + 4050 VA + 3500 VA + 0 VA = 14225 VA

Neutral Load in Amperes:

59A ( 14225 VA/240V)

4. Supply-side Bonding Jumper Size [250.102(C)]​

Supply-side bonding jumper sized to the service conductor size.

5. Raceway Size [Chapter 9, Table 1]​

Based on a raceway at 40% fill, with an equipment grounding conductor.

Guess I was looking for more of an understanding of the actual heat generation in the conductor than regurgitated code info, but thanks anyway guys.
Code doesn’t really matter to me, I’m not trying to sell my house with the wall-connector installed. I do know that it matters how long the conductor is when you’re talking about the current-carrying capacity of the wire, but there’s no mention of how long or short a #6 copper wire can be in that rating on the spool.

My six foot long #6 wire really does stay room temp with 48 amps flowing through it while the ten foot cable going to the car from the wall connector gets slightly warm.

But yeah, I’ll set it down to 50amp circuit and pick up a 50A breaker today. I don’t actually need 44 miles/hr, nor do I need my homeowners insurance policy being canceled because I posted about this online lol

I suggest that code should matter to you for your own safety. Length has to do with voltage drop, not its ampacity.

Heat generation is a function of resistance in the wire; more resistance = more heat. Shorter length of wire = less resistance. Your 6' of #6 Romex, while not conforming 100% to code, will not heat up compared to 100' of it.

The heat per foot will be the same.

Practically speaking you’ll never have an issue with your setup. NM-B (Romex) is de-rated to the 55c temperature limit because under extreme conditions - long runs through attics, super high-temp environments, etc - the insulation retains more heat than conduit and doesn’t dissipate it as effectively.

Is a six foot run in San Diego ever gonna be in conditions like that to cause problems? No. Is it to code? No.

All the above said, this is true too.

 

[DuncanM]

That is why I said OP should "install the largest circuit that he can install economically".

You don't add up all the breakers to see if a panel is overloaded. Rather you do a load study.

Every house I have done a load study for that had 200 amp service had no problem with a 60 amp (48 amp charging) EV circuit.

The OP stated that he had little electrical knowledge, so I used an example of 240v breakers in my panel and their associated loads; I suggested that he consult an electrician to do a load study. Some of my neighbours, in our rural area, have two separate heat pump setups, and 240v circuits for their well water pumps (ours is on a seperate meter and panel) and in one a 50amp 240v outlet for an electric welder and in another a 240V RV circuit, and at least in two cases they opted for a 400amp main panel. I didn't mention that my garage, and 240V EVSE charging circuit, was fed by a subpanel with a 50A/240v main breaker.

In any event, adding a 60amp breaker for a potential continuous 48A/240V load is not something to be done without careful consideration of overall loads on the main breaker; for all we know the OP has a 100amp main breaker.

 

[Eric33432]

The OP stated that he had little electrical knowledge, so I used an example of 240v breakers in my panel and their associated loads; I suggested that he consult an electrician to do a load study. Some of my neighbours, in our rural area, have two separate heat pump setups, and 240v circuits for their well water pumps (ours is on a seperate meter and panel) and in one a 50amp 240v outlet for an electric welder and in another a 240V RV circuit, and at least in two cases they opted for a 400amp main panel. I didn't mention that my garage, and 240V EVSE charging circuit, was fed by a subpanel with a 50A/240v main breaker.

In any event, adding a 60amp breaker for a potential continuous 48A/240V load is not something to be done without careful consideration of overall loads on the main breaker; for all we know the OP has a 100amp main breaker.

I stand behind my statement in my original email, which I quote:

"Any 240 volt charging will top off your car overnight, but there may be a few times when you want to charge your M3 more quickly than overnight, so install as large a circuit as your electrical service will economically allow (up to 60 amps)."

And to post information that says to add up your 240 volt breakers to determine the load on your electrical service is doing a dis-service to the people who read this forum, especially people with limited electrical knowledge.

 

[DuncanM]

I stand behind my statement in my original email, which I quote:

"Any 240 volt charging will top off your car overnight, but there may be a few times when you want to charge your M3 more quickly than overnight, so install as large a circuit as your electrical service will economically allow (up to 60 amps)."

And to post information that says to add up your 240 volt breakers to determine the load on your electrical service is doing a dis-service to the people who read this forum, especially people with limited electrical knowledge.

Again, the OP admits to having little knowledge of electrical loads.

I posted an example of the loads on my panel with caveats regarding continuous loads and a recommendation to have a load study done by an electrician; drawing attention to existing loads is hardly disinformation or a disservice to anyone. especially someone with limited electrical knowledge.

 

[Eric33432]

Again, the OP admits to having little knowledge of electrical loads.

I posted an example of the loads on my panel with caveats regarding continuous loads and a recommendation to have a load study done by an electrician; drawing attention to existing loads is hardly disinformation or a disservice to anyone. especially someone with limited electrical knowledge.

Adding up breakers to determine your load is simply wrong so it is disinformation.

 

[DuncanM]

Adding up breakers to determine your load is simply wrong so it is disinformation.

Nope. I enumerated my 240v loads and gave the associated breaker sizes and I stated that the loads are likely to be 20% less than the breaker amperage; I did this to draw awareness of existing loads vs panel capacity. Obviously, if I had stated more 240V loads there would be a point where the total, potential loads, could exceed the main breaker capacity when we add a 48amp/240V continuous load on top of the existing loads. Again, I recommended a load study be done by an electrician.

Again, we don't know the OP's main breaker size, do we? In fact we know nothing about the OPs existing loads.

 

[Eric33432]

Nope. I enumerated my 240v loads and gave the associated breaker sizes and I stated that the loads are likely to be 20% less than the breaker amperage; I did this to draw awareness of existing loads vs panel capacity. Obviously, if I had stated more 240V loads there would be a point where the total, potential loads, could exceed the main breaker capacity when we add a 48amp/240V continuous load on top of the existing loads. Again, I recommended a load study be done by an electrician.

Again, we don't know the OP's main breaker size, do we? In fact we know nothing about the OPs existing loads.

You obviously do not understand.

First, your statement to add up the loads, even with a 20% discount, has nothing to do with the size of the service needed, and you also added that 48 amp charging would likely trip your main breaker. This is disinformation. Your recommendation to have a load study done does not correct your earlier disinformation. And this has nothing to do with the size of the OP's electrical service.

This will be my last comment on this thread. Go ahead and have the last word.

 

[DuncanM]

You obviously do not understand.

First, your statement to add up the loads, even with a 20% discount, has nothing to do with the size of the service needed, and you also added that 48 amp charging would likely trip your main breaker. This is disinformation. Your recommendation to have a load study done does not correct your earlier disinformation. And this has nothing to do with the size of the OP's electrical service.

This will be my last comment on this thread. Go ahead and have the last word.

I will have the last word. I drew attention to the loads on my panel, and I used language that the OP could understand, by simply looking at his panel.

You seem to be suggesting that 200amp panels have unlimited load capacity, since you've never discovered a case where this wasn't true, yet we all know that in some cases a panel with a larger capacity main breaker is required.

 

[Rocky_H]

Yes, the Tesla wall connectors are a surprisingly good value for their capability and cost.

On the technique of asking an electrician for the estimate, I will suggest that people sometimes do this in a way that is doing themselves a disservice. Don't start off with this as a statement:
"I want a 60A circuit."

What if you don't have enough spare capacity for adding an extra full 60A circuit? Maybe you only have 42A to spare? Well, they're going to do what you demanded and quote up whatever upgrades would be necessary to make the 60A happen. That may be pricey, where you don't need that and it's not worth it.

So I just suggest asking it as a question:
"Can you do a load calculation and tell me how big a circuit I have room to add?"

 

[3sr+buyer]

I am looking to have a wall connector installed in my garage. There are several options available both the Tesla brand and others. I am dead set on buying a Tesla M3, although not sure it it will be Standard or Long range.

Unless there is a subsidy program that makes other wall-mount EVSEs significantly less expensive, the Tesla Wall Connector is probably the best choice for a wall-mount EVSE for charging a Tesla. For charging both a Tesla and a non-Tesla with a J1772 inlet, the Tesla Universal Wall Connector may be worth considering.

 

[kpanda17]

My local utility, like most in the USA, are subsidizing way overpriced less functional, non Tesla integrated WCs as a fakeout to then become big brother, like the thermostat offers by them, as to cut the EV charging off during a brownout
I get the reason, but don’t want big brother preventing me charging my EV
And like stated, these are less superior WCs
JD Power has rated the Tesla WCs are the best

 

[3sr+buyer]

My local utility, like most in the USA, are subsidizing way overpriced less functional, non Tesla integrated WCs as a fakeout to then become big brother, like the thermostat offers by them, as to cut the EV charging off during a brownout
I get the reason, but don’t want big brother preventing me charging my EV

Wouldn't time-of-use electricity pricing already create incentives to avoid charging an EV during the time when brownouts are most likely to occur (peak hours in the late afternoon and early evening)? Seem that this type of subsidized EVSE that the utility can turn off scheme is neither necessary nor much of an impact for the customer who does EV charging at home.

The subsidized thermostat that the utility can adjust scheme has more effect in both aspects, since peak hour summer air conditioning use is a huge factor in possibly overloading the grid and generation capacity. (Some people with AC time-shift their AC use to pre-cool their house before peak hours start, then turn off the AC during peak hours.)

 

[ATPMSD]

Unless there is a subsidy program that makes other wall-mount EVSEs significantly less expensive, the Tesla Wall Connector is probably the best

Wall Connector $450 + Standard Breaker $15 = $465
Mobile Connector $250 + GFCI Breaker $150 (required by code) + Bryant or Hubbell outlet $80 (these are designed for the high-continuous loads of an EV) and some sort of cable management system $35 = $515

So the wall connector is cheaper without any rebates,

 

[ATPMSD]

Sorry, @3sr+buyer, I missed the word "other" in you response.

 

[3sr+buyer]

Wall Connector $450 + Standard Breaker $15 = $465
Mobile Connector $250 + GFCI Breaker $150 (required by code) + Bryant or Hubbell outlet $80 (these are designed for the high-continuous loads of an EV) and some sort of cable management system $35 = $515

So the wall connector is cheaper without any rebates,

Huh? The OP is considering only wall-mount EVSEs, not portable ones (although some of your estimated prices around the Mobile Connector option are higher than likely actual). The comparison would be other wall-mount EVSEs like the ones from ChargePoint, Grizzl-E, Autel, etc.

 

[ATPMSD]

Huh? The OP is considering only wall-mount EVSEs, not portable ones (although some of your estimated prices around the Mobile Connector option are higher than likely actual). The comparison would be other wall-mount EVSEs like the ones from ChargePoint, Grizzl-E, Autel, etc.

Read post #55

 

[davewill]

My local utility, like most in the USA, are subsidizing way overpriced less functional, non Tesla integrated WCs as a fakeout to then become big brother, like the thermostat offers by them, as to cut the EV charging off during a brownout
I get the reason, but don’t want big brother preventing me charging my EV
And like stated, these are less superior WCs
JD Power has rated the Tesla WCs are the best

I don't understand. If you get the reason, then why call it a "fakeout to then become big brother"? The logic is simple enough, shed enough non-essential loads and you don't have to do a general black or brownout that might kill people or damage equipment. Nothing "fake" about intelligent management of the grid.

Besides, it's Tesla's fault that their equipment doesn't qualify for so many of these subsidies. Their hardware could easily do it, they just can't be bothered to implement. For a long time, they didn't even have Energy Star compliance which kept them from qualifying for so many subsidy programs and which had nothing to do with remote control.

If I ever have to replace an EVSE, I'll probably go Tesla, but I'd happily partipate in a load shedding program, if one were available here.

 

[kpanda17]

I don't understand. If you get the reason, then why call it a "fakeout to then become big brother"? The logic is simple enough, shed enough non-essential loads and you don't have to do a general black or brownout that might kill people or damage equipment. Nothing "fake" about intelligent management of the grid.

Besides, it's Tesla's fault that their equipment doesn't qualify for so many of these subsidies. Their hardware could easily do it, they just can't be bothered to implement. For a long time, they didn't even have Energy Star compliance which kept them from qualifying for so many subsidy programs and which had nothing to do with remote control.

If I ever have to replace an EVSE, I'll probably go Tesla, but I'd happily partipate in a load shedding program, if one were available here.

In the past we had brownouts, old grid not able to handle peaks
then the utilities added Peaker plants (coal/nat gas) to handle the peaks
now the utilities are rapidly adding BESS to handle the peaks (retiring peaker plants)
In VT they paid for people to add powerwalls to their homes for distributed VPP
In NY the local utility is subsidizing powerwall investing by homeowners for eventual VPP (think its not active yet)
I'm not 100% sure of the rights of the actual owner of the VPP/PW (dont think applies to VT) for controlling the flow, PW to my home at night or I can temp opt in to help the grid
thats my point, an opt in
its a fakeout if you have no opt out ability, control for the flow direction, or they wont detail what you are signing up for, I dont want big brother

 

[Rocky_H]

its a fakeout if you have no opt out ability, control for the flow direction, or they wont detail what you are signing up for, I dont want big brother

OK, sure. But you're saying all of this negative stuff about things that ARE opt-in and at the discretion of the homeowner. The power companies are offering financial incentives to install some of these things that will benefit load management (like the price savings off of a charging station), but you are free to turn down the money and buy something else that doesn't use that.

We have a really good and appropriate program around here from Idaho Power that is called the "A/C Cool Credit" program. You can opt in or opt out. If you opt in, you get a $5 discount off your monthly bill. They install a little wireless control on your air conditioning unit, so that they can disable it from activating for some short portions of time. So they can rotate through groups of houses to limit A/C draw. But let's say you are having a big party in July with friends over, you do get some number of days a year to file for saying "Don't use that on this day, because I need to keep it fully cool."

It's a decent win/win, and they're getting enough uptake just by offering money incentives.