How much should the HOA charge? (I'm the HOA president)

[Earl]

every building's electrical panel has a finite load capacity.

Nonsense. It is perfectly possible to upgrade. Just expensive.
Best case: put in a bigger transformer (if there is room and a big enough service on the street)
Worst case:
- run a new line to the site
- dig a new transformer vault
- run new wiring to the units

Granted:
"Best case" will cost probably $20K to $40K
"Worst case" will cost probably $40K to $60K + a lot per unit depending on the distance

 

[DuncanM]

OK, then let me put this another way. Why put in 10 lines of 120V instead of 5 lines of 240V? That would be the same power load on the panel, but the 120V lines would cost twice as much for the installation, be hardly useful at all, and intensely frustrating for the residents. Minimum reasonable usefulness needs to be a consideration in things like this, even if there needs to be some sharing or reserving or whatever among residents.

A 200amp/208v (sub)panel can supply about 30 x 110v NEMA 5-15 outlets, each on it's own breaker, through distributed subpanels

30 residents have access to charging at their stalls and each can supply their own low cost L1 EVSE and meter and can use the outlet for other things as desired.

I agree that shared L2 chargers are a good idea, but then you have the issue of how many parking stalls have to be dedicated to charging? In our building we have no spare parking stalls and there's a wait list for the existing stalls. What will happen is that at 5-10pm when demand is highest, everyone and their dog will want to use the L2 chargers and they will need to be there for several hours, at least, each. Again, shared L2 chargers seem like a great idea now, when few people are charging, but if we have mass adoption it won't work.

 

[Earl]

A 200amp/208v (sub)panel can supply about 30 x 110v NEMA 5-15 outlets, each on it's own breaker, through distributed subpanels

30 residents have access to charging at their stalls and each can supply their own low cost L1 EVSE and meter and can use the outlet for other things as desired.

I agree that shared L2 chargers are a good idea, but then you have the issue of how many parking stalls have to be dedicated to charging? In our building we have no spare parking stalls and there's a wait list for the existing stalls. What will happen is that at 5-10pm when demand is highest, everyone and their dog will want to use the L2 chargers and they will need to be there for several hours, at least, each. Again, shared L2 chargers seem like a great idea now, when few people are charging, but if we have mass adoption it won't work.

I don't get the math.
200 amps/30 outlets = 13 amps per outlet at 104 volts. A 5-15 outlet is supposed to be connected to a 20 amp breaker. I think you're violating code and the NEC.
Some Tesla models can have their charge current dropped to as low as 5 amps manually but I wouldn't count on most owners to be able to consistently ensure they've done so. They are more likely to just plug in. If many do this simultaneously, you'll blow the 200 amp breaker and nobody will charge. If the breaker doesn't work, you could burn the complex down too.
This sounds like a dangerous situation in addition to violating code.
You might be able to get 20 legal and safe 5-15 outlets.

 

[SalisburySam]

A 200amp/208v (sub)panel can supply about 30 x 110v NEMA 5-15 outlets, each on it's own breaker, through distributed subpanels

30 residents have access to charging at their stalls and each can supply their own low cost L1 EVSE and meter and can use the outlet for other things as desired.

I agree that shared L2 chargers are a good idea, but then you have the issue of how many parking stalls have to be dedicated to charging? In our building we have no spare parking stalls and there's a wait list for the existing stalls. What will happen is that at 5-10pm when demand is highest, everyone and their dog will want to use the L2 chargers and they will need to be there for several hours, at least, each. Again, shared L2 chargers seem like a great idea now, when few people are charging, but if we have mass adoption it won't work.

There will always be lots of “reasons” and probably unlimited “use cases” and odd “scenarios” in which anything less than a full L3 charging station in every parking slot just won’t work. This is the “perfect” getting in the way of the “good” and causing action paralysis. How about just doing “something” that can meet a certain level of low expectations, and see how it goes from there?

 

[DuncanM]

I don't get the math.
200 amps/30 outlets = 13 amps per outlet at 104 volts. A 5-15 outlet is supposed to be connected to a 20 amp breaker. I think you're violating code and the NEC.
Some Tesla models can have their charge current dropped to as low as 5 amps manually but I wouldn't count on most owners to be able to consistently ensure they've done so. They are more likely to just plug in. If many do this simultaneously, you'll blow the 200 amp breaker and nobody will charge. If the breaker doesn't work, you could burn the complex down too.
This sounds like a dangerous situation in addition to violating code.
You might be able to get 20 legal and safe 5-15 outlets.

Each outlet has a dedicated breaker and putting a 20amp breaker on a single NEMA 5-15 outlet seems to me to be a bad idea, since we want the 15amp breaker to kick to protect the panel/subpanel main breakers. But in any event, even if code requires changes, you get the idea.

 

[Earl]

Each outlet has a dedicated breaker and putting a 20amp breaker on a single NEMA 5-15 outlet seems to me to be a bad idea, since we want the 15amp breaker to kick to protect the panel/subpanel main breakers. But in any event, even if code requires changes, you get the idea.

I get the idea when I see scorched 5-15 outlets and plugs. This isn't some little 500mW USB cellphone charger we're talking about here. It is serious power being transferred.
Please don't do something stupid and give EV's a black eye in the press.
The electrical code is not there to preserve the feel of the neighborhood like setback and design codes are. It's there for real safety. While I may stretch it a bit personally, I'd never install something that breaks code in a condo with many people who don't even know how to take care of their own houses.

 

[Blackshirt]

If the HOA is going to support EV charging by allowing charging on their breakers the HOA needs something like the Juice Box that is access controlled. Without a code, it will not charge. Usage is billed to each unique code.
The install could be paid by the HOA or the users by increasing usage fee or an initial user setup fee to recover HOA install. Enough EVs join up you add more Juice Boxes. Atom Power has digital breaker EV setups if you want to go high end.

 

[DuncanM]

I get the idea when I see scorched 5-15 outlets and plugs. This isn't some little 500mW USB cellphone charger we're talking about here. It is serious power being transferred.
Please don't do something stupid and give EV's a black eye in the press.
The electrical code is not there to preserve the feel of the neighborhood like setback and design codes are. It's there for real safety. While I may stretch it a bit personally, I'd never install something that breaks code in a condo with many people who don't even know how to take care of their own houses.

You're making assumptions here that a 15amp breaker (the ideal would a 12amp breaker at the subpanel or at the outlet) won't protect a NEMA 5-15 outlet and that 20amp breakers are mandatory when they're not. An electrical engineer would have to design the actual circuits but the idea is simple; lots of outlets to service all or most of the available parking stalls, with individual owners taking it from there.

 

[Eric33432]

I don't get the math.
200 amps/30 outlets = 13 amps per outlet at 104 volts. A 5-15 outlet is supposed to be connected to a 20 amp breaker. I think you're violating code and the NEC.
Some Tesla models can have their charge current dropped to as low as 5 amps manually but I wouldn't count on most owners to be able to consistently ensure they've done so. They are more likely to just plug in. If many do this simultaneously, you'll blow the 200 amp breaker and nobody will charge. If the breaker doesn't work, you could burn the complex down too.
This sounds like a dangerous situation in addition to violating code.
You might be able to get 20 legal and safe 5-15 outlets.

Firstly, the voltage will be ~120 volts, not 104 volts. If 30 cars were charging at 12 amps each, all at the same time, at 120 volts, the amount of power being used would be 12 x 120 x 30 = 43,200 watts. But it is unlikely that all 30 cars would be charging at the same time.

A 208/120 volt panel implies that it is 3 phase. At 200 amps this is 72 kW (200 x 208 x 1.73 = 71,968). So the 30 120 volt outlets would not overload the panel.

The NEMA 5-15 outlets should be protected by 15 amp breakers. If you used 20 amp circuits, with NEMA 5-20 outlets, the total power used would be 57,600 watts if all the cars were charging at the same time at 16 amps each.

This 72 kW of available power could easily be shared between 30 Tesla Wall Connectors. There could be 5 groups of 6 wall connectors, each group sharing a 60 amp circuit. The amount of power being used would max at 60 kW (48 x 208 x 6 = 59,904)

Even if everyone plugged in at 5 PM, the cars do not all have to charge at the same time, and it is unlikely that all cars would arrive at exactly the same time. The Tesla Wall Connectors would manage the power sharing, and allow the maximum utilization of the available power, and also can manage the billing.

There are probably other EVSE that could do the same thing; I am only familiar with the Tesla Wall Connector.

 

[Rocky_H]

A 200amp/208v (sub)panel can supply about 30 x 110v NEMA 5-15 outlets, each on it's own breaker, through distributed subpanels

30 residents have access to charging at their stalls and each can supply their own low cost L1 EVSE and meter and can use the outlet for other things as desired.

...which people will hate and not want to use because it is so insufficient for charging. This is the fundamental issue. My grandma used to have a saying for this when someone would cut a little slice of pie to serve to her:
"That's just enough to make you mad!"

 

[Big Earl]

This is worth a read regarding Tesla commercial and multi-unit charging.

https://digitalassets.tesla.com/tesla-contents/image/upload/Tesla_Wall_Connector_ApplicationNote.pdf

Note: while you can install more units on a 225 amp panel, Tesla recommends the above for the best user experience depending on application (apartment vs condo).

 

[DuncanM]

...which people will hate and not want to use because it is so insufficient for charging. This is the fundamental issue. My grandma used to have a saying for this when someone would cut a little slice of pie to serve to her:
"That's just enough to make you mad!"

Sorry but that's not the case. The average daily commute/EV power consumption in the USA/Canada is just about the same distance which a 110v/8-10a outlet can provide in ~8-10 hours. Yes for some, their car's SOC will decline during the week, but they'll have enough range remaining to get to work and back. There will be a few (uber drivers and a few with very long commutes for example) who might have to rely on public DCFCs to top up.

Imagine the infrastructure cost if the public ICE refueling network had to provide enough capacity for every ICE vehicle to fill from empty to full every day!

I think the issue here is the idea that only high Kw charging is 'real' charging and nothing else is worth looking at; I know from personal experience that this is not the case. The two cars in our condo (a 55+ strata) that have dedicated 208v/40a outlets sit in their stalls most of the time with the cars unplugged...Crazy!

I have friends in downtown Toronto. Their large condo complex (again no spare parking spaces) has received bids of ~300 grand/cdn to install a 208v high amperage system to a small fraction of the cars in their UG parking (federal subsidies will make up some of the cost). Each owner who decides to join the scheme will be on the hook for about 4 grand in up front costs and then regular fees for network access and billing, on top of the actual power consumed. My friends are retired and want an EV but they do very little in the way of daily driving and the cost and complexity of the proposed system has soured them completely on EVs and the public AC/DCFC charging network is downtown Toronto will always be limited. Both Canada and the USA have a high proportion of retirees in Condos and they simply don't need or want to pay the equivalent of a lifetime of charging at the going kwh rate just to get access to an electrical outlet at their parking stall!

 

[Rocky_H]

I think the issue here is the idea that only high Kw charging is 'real' charging and nothing else is worth looking at;

No, I know what you're saying, where I also fight against this dumb notion that "Overkill still isn't enough!!!!" and everyone thinks they need 60 or 80 amp circuits as a bare minimum. But you're pushing into the error on the other end. I like 240V 20A circuits or 240V 30A. Those are not "high kW charging", but are very useful. It's the 120V circuits that are so low as to be frustrating and not very effective. You have to depend on it every single day without fail because you get so little from it. And if it's cold, the car sometimes barely gets any charging at all. It's just too problematic to be the thing to go for.

 

[ai4px]

That just doesn't really make any sense to intentionally target doing 120V lines, because of:

Exactly. The cost difference of putting in either a 120V 15A outlet or a 240V 15A outlet is $0. There is no point putting in something that only provides half the power, when the installation and equipment cost are literally the same.

@DuncanM Since you're talking about "expand access to 110V outlets", that means running new wire to locations. So that's the cost outlay anyway. Using 120V on that instead of 240V just doesn't make sense, since it's the same wire.

You are correct... but ... when I contacted the Columbia Airport in South Carolina, I spoke to the facilities manager about installing 120v outlets in the parking garage. I was trying to explain to him that there was no need for expensive j1772 charge stations. 120v would be great becuas even if it took 3 days to charge my car, if I was flying i'd be gone 3 days and back. By putting 120v instead of 208 or 240, they could service more individual outlets.

Just a perspective.

 

[gt2690b]

You are correct... but ... when I contacted the Columbia Airport in South Carolina, I spoke to the facilities manager about installing 120v outlets in the parking garage. I was trying to explain to him that there was no need for expensive j1772 charge stations. 120v would be great becuas even if it took 3 days to charge my car, if I was flying i'd be gone 3 days and back. By putting 120v instead of 208 or 240, they could service more individual outlets.

Just a perspective.

120 5-20 outlets at airport parking is certainly not a bad idea but for basically the same installation costs you could do something like 240V nema 6-20s or maybe even both with a neutral just because you are wasting so much power charging at 120V

Alternatively you could spend the up front capital for real chargers and charge per kw to make up for your costs (and some) and you'd likely not even need as much capacity as dedicated 120v outlets because the chargers would manage the load and you wouldn't be wasting 40% on inefficiencys

 

[DBeckwith]

This is worth a read regarding Tesla commercial and multi-unit charging.

https://digitalassets.tesla.com/tesla-contents/image/upload/Tesla_Wall_Connector_ApplicationNote.pdf

Note: while you can install more units on a 225 amp panel, Tesla recommends the above for the best user experience depending on application (apartment vs condo).

I wish they would suggest spending more to locate charging spots further from building to avoid ICEing. I personally know of several cases where ignoring this results in failure.

 

[MP3Mike]

And if it's cold, the car sometimes barely gets any charging at all. It's just too problematic to be the thing to go for.

This is very true. I currently only have 240v 20A charging, and there are times when it is cold that that isn't even enough to get any charge at all. It spends all of the energy trying to heat the battery, but never gets it warm enough to accept a charge. Other than that, I haven't had any issues with ~3.8kW charging setup.

The 2.5x overhead for using a 120v 15A outlet would be a non-starter for me. (This calculator shows that it would cost more than $200 a year.)

I think it would be more than worth it to invest in the extra $500-600 per spot to put load balanced Wall Connectors which gets you a number of advantages, for example:

• Built-in billing functionality.
• Ability to charge faster when others aren't charging.

 

[DuncanM]

Sorry but that's not the case. The average daily commute/EV power consumption in the USA/Canada is just about the same distance which a 110v/8-10a outlet can provide in ~8-10 hours. Yes for some, their car's SOC will decline during the week, but they'll have enough range remaining to get to work and back. There will be a few (uber drivers and a few with very long commutes for example) who might have to rely on public DCFCs to top up.

Imagine the infrastructure cost if the public ICE refueling network had to provide enough capacity for every ICE vehicle to fill from empty to full every day!

I think the issue here is the idea that only high Kw charging is 'real' charging and nothing else is worth looking at; I know from personal experience that this is not the case. The two cars in our condo (a 55+ strata) that have dedicated 208v/40a outlets sit in their stalls most of the time with the cars unplugged...Crazy!

I have friends in downtown Toronto. Their large condo complex (again no spare parking spaces) has received bids of ~300 grand/cdn to install a 208v high amperage system to a small fraction of the cars in their UG parking (federal subsidies will make up some of the cost). Each owner who decides to join the scheme will be on the hook for about 4 grand in up front costs and then regular fees for network access and billing, on top of the actual power consumed. My friends are retired and want an EV but they do very little in the way of daily driving and the cost and complexity of the proposed system has soured them completely on EVs and the public AC/DCFC charging network is downtown Toronto will always be limited. Both Canada and the USA have a high proportion of retirees in Condos and they simply don't need or want to pay the equivalent of a lifetime of charging at the going kwh rate just to get access to an electrical outlet at their parking stall!

I just checked with my friends in downtown Toronto and the buy-in is 6 grand/cdn per stall!

 

[gt2690b]

I just checked with my friends in downtown Toronto and the buy-in is 6 grand/cdn per stall!

its Canadian though so its only like 50 cents

 

[DuncanM]

This is very true. I currently only have 240v 20A charging, and there are times when it is cold that that isn't even enough to get any charge at all. It spends all of the energy trying to heat the battery, but never gets it warm enough to accept a charge. Other than that, I haven't had any issues with ~3.8kW charging setup.

The 2.5x overhead for using a 120v 15A outlet would be a non-starter for me. (This calculator shows that it would cost more than $200 a year.)

I think it would be more than worth it to invest in the extra $500-600 per spot to put load balanced Wall Connectors which gets you a number of advantages, for example:

• Built-in billing functionality.
• Ability to charge faster when others aren't charging.

Many condo complexes have underground parking, with stable year round temperatures. I think most forum members are dramatically underestimating the cost for installing complete L2 charging systems rather vs the cost of a simple 110v outlet.