Condo got budget approved for 2 chargers - electrician is installing a new 200 amp service (to expand later) - should we buy 40amp or 48amp chargers?

[NewEnglandCld]

I'm on the board of my COA and have been the project manager for getting EV chargers installed at our building. I just got some budget approved and we're going to start with 2 chargers, but want to have some room to expand down the line.

We're going to put in two units, and I'm trying to decide whether to go with the 48amp units of the 40amp?

For reference, the electrician is doing a: Installation of New 200 amp 3 phase 120/208v service to serve the level 2 electric car chargers. 200 amp 3 phase 30/60 circuit NEMA 3r load center to be installed to provide power for the (2) chargers to be installed as well as providing adequate space for future expansion if additional chargers or other equipment are to be installed.

 

[ATPMSD]

You do not need or want 3-phase power, most EV connectors do not support 3-phase power. You want standard 120/240v single phase (split phase). A 200-amp service panel sill support 3-wall connectors. 200-amps can support 160-amp of continuous drawn. 3-units at 48A each is only 144-amps. It will also support 4-units at 40-amps each.

 

[NewEnglandCld]

You do not need or want 3-phase power, most EV connectors do not support 3-phase power. You want standard 120/240v single phase (split phase). A 200-amp service panel sill support 3-wall connectors. 200-amps can support 160-amp of continuous drawn. 3-units at 48A each is only 144-amps. It will also support 4-units at 40-amps each.

So I tell my electrician do to a signal (split phase) instead? Is that going to impact cost?

 

[ATPMSD]

So I tell my electrician do to a signal (split phase) instead? Is that going to impact cost?

Should be cheaper. You really should get a copy of the owner’s manual for what you want to install and show it to the electrician so he can comply with the manufacturer’s specifications. This should be the link for the Tesla Gen 3 Wall Connector:

https://www.tesla.com/sites/default/files/support/charging/Gen3_WallConnector_Installation_Manual.pdf

 

[ATPMSD]

trying to decide whether to go with the 48amp units of the 40amp?

But to answer your actual question, I would run full 60-amp circuits so you can get the 48-amps. You can always dial it down later or, in the case of the Tesla Wall Connector, it has built in power sharing.

 

[NewEnglandCld]

Should be cheaper. You really should get a copy of the owner’s manual for what you want to install and show it to the electrician so he can comply with the manufacturer’s specifications. This should be the link for the Tesla Gen 3 Wall Connector:

https://www.tesla.com/sites/default/files/support/charging/Gen3_WallConnector_Installation_Manual.pdf

We were going to do the Pulsar Plus 48. I can’t seem to find much documentation on single vs 3 phase for this charger: Wallbox Pulsar | Compact and efficient charger

 

[pb2000]

Three phase power is perfectly fine and is probably the only choice available to you. 208V is just the phase to phase voltage and works perfectly fine other than the slight power reduction, so ignore everything ATPSMD has said.

48A is probably a good idea for the first chargers if the stalls are dedicated and people are expected to move their vehicle after charging.

 

[ATPMSD]

Three phase power is perfectly fine

Not on the U.S. version! At least for Tesla

Voltage and Wiring: Nominal 200-240 V AC single-phase

 

[pb2000]

All power is 3 phase, but you can take any of the two phases and use it as a single phase.

 

[ATPMSD]

We were going to do the Pulsar Plus 48. I can’t seem to find much documentation on single vs 3 phase for this charger: Wallbox Pulsar | Compact and efficient charger

I found this, which I “think” is yours?

https://support.wallbox.com/wp-content/uploads/ht_kb/2021/01/Pulsar-Plus-N.-A.-Installation-Guide.pdf

There is no mention of to “phases” as there is in the Tesla manual. I would give them a call.

 

[pb2000]

Please stop misleading the OP. You are wrong and clearly do not understand how the electrical grid works.

 

[ATPMSD]

None the less it is a waste of money to run 3-phase power when it is not needed.

 

[Tronguy]

Um. Going back to the 3-phase stuff. Commercial power is usually 3-phase; that's how it comes from the utility, anyway.

Each phase to ground/neutral is 120 VAC. From phase to phase (that is, hot to hot) one gets 208 VAC. If the phases are labeled A, B, and C, and the neutral is N, then (A->N), (B->N), and (C->N) are all 120 VAC. (A<->B), (A<->C), and (B<->C) are all 208 VAC. Finally, for a quiz about to appear, if Phase A is at 0 degrees, Phase B is at 120 degrees, and Phase C is at 240 degrees.

208 VAC counts as Level 2 and is handled by the car as such.

Now, Ye Normal non-Commercial Suburban House gets split phase: That is, each phase is 120 VAC to Neutral/Ground, but the phases are of equal and opposite phase. So, in this split-phase approach, if Phase A is at 0 degrees, Phase B will be at 180 degrees. So, the voltage from (A<->B) is 240 VAC.

So, ye normal house breaker box has a bunch of breakers, horizontally oriented, stacked one on top of another. They alternate between Phase A and Phase B. So, if you want 240 VAC for the furnace or air conditioner, they gang two breakers into two slots; the two wires coming out of the two breakers are both, "hot", and the voltage between them is 240 VAC.

I've never, personally, messed with a three-phase system, but I'm sure your electrician has. I'd guess that the slots are ABCABCABC on the phases, but the electrician knows more.

Having said all that: Let's talk about power. If you're in a house and you've got a pair of 60A breakers giving you 240 VAC, then the max load with a Tesla will give you 48A. 240 VAC * 48A = Power = 11.52 kW. If, for some reason, you'd like to run 40A with a 50A breaker, then the power would be 240V * 40A = 9.6 kW.

Now, say you're in a commercial establishment. All they have is 3-phase. You can still get 48A, but the voltage for Level 2 will be 208V. With 60A breakers, the power level will be 208 * 48 = 9.98 kW. With 50A breakers, you'll get 208 * 40 = 8.32 kW.

All right. If commercial power is what you've got (and it's a condo, it might be all they've got, it's the power company that decides upon the transformer, I'm pretty sure), then 208 is in your future.

What's this do for charging times?

Consider a Model 3. It gets 250 W-hr per mile. So, the charging rates are as follows:
240 VAC @ 48A = 11.52 kW. 11.52 kW/(0.25 kW-hr/Mile) = 46 Miles/Hour
240 VAC @ 40A = 9.6 kW. 9.6 kW/(0.25 kW-hr/Mile) = 38.4 Miles/Hour
208 VAC @ 48A = 9.98 kW. 9.98 kW/(0.25 kW-hr/Mile) = 39.9 Miles/Hour
208 VAC @ 40A = 8.32 kW. 8.32 kW/(0.25 kW-hr/Mile) = 33.28 Miles/Hour.

So, suppose you got a M3 that can hold 310 miles of charge and it shows up with ten miles left on it. With 208 @ 40A it'll take it maximum time of 300/33.28 = 9 hours for a full charge to 100%; with 240 VAC at 48A it'll get to full charge at 300/46 = 6.76 hours. You'll note that both of these times come under the category of Overnight. Finally, nobody sane charges to 100% unless they've got a long trip ahead of them; usually it's 90%. And normally people don't wait until the car's dead near empty before charging: That's why you've got the charging stations in the first place. So, a more "normal" charging regime would be like, say, 200 or 150 miles, which would be three or four hours of charging.

Fine. That's how it works for a Tesla. You got a different Tesla (MY, MX, MS) they all got different W-hr/mile, it was on the sticker that came with the car.

You got other cars: Teslas max out at a current of 48A when playing with L2 AC. There are other BEVs in the world, they generally take the J1772 connector. I don't happen to know if the J1772 adapter that comes with every Tesla can handle 48A. Wikipedia claims a J1772 can do 80A, but I don't know if the adapter supports that or not.

If you want to support stuff that's not Teslas, there's charging stations/wall connectors that support J1772 at currents at or higher than 48A, but these are usually more expensive, by a hundred bucks or two, than the Tesla Wall Connector.

Frankly, I don't see that much difference between using 3-phase or 2-phase, at least in terms of time. But if it's zero cost to go for a split phase transformer from the (usual) 600VAC or 400 VAC that the power company uses as compared to a three-phase, then, what the heck, go for the split phase.

You got questions, we got answers.

 

[pb2000]

None the less it is a waste of money to run 3-phase power when it is not needed.

No, exactly the opposite - you get 1.73x more power with just one more wire.

@Tronguy Thanks, I don't have the patience today for writing out a technical and detailed post, so I appreciate you stepping in.

 

[Bella42]

I live in an apartment complex and 3 phase 208 volts is what I have and my Tesla Wall connector doesn't mind the missing 32 volts. I charge normally and always have with this setup since Jan 2022.

 

[ATPMSD]

Um. Going back to the 3-phase stuff. Commercial power is usually 3-phase; that's how it comes from the utility, anyway.

Each phase to ground/neutral is 120 VAC. From phase to phase (that is, hot to hot) one gets 208 VAC. If the phases are labeled A, B, and C, and the neutral is N, then (A->N), (B->N), and (C->N) are all 120 VAC. (A<->B), (A<->C), and (B<->C) are all 208 VAC. Finally, for a quiz about to appear, if Phase A is at 0 degrees, Phase B is at 120 degrees, and Phase C is at 240 degrees.

208 VAC counts as Level 2 and is handled by the car as such.

Now, Ye Normal non-Commercial Suburban House gets split phase: That is, each phase is 120 VAC to Neutral/Ground, but the phases are of equal and opposite phase. So, in this split-phase approach, if Phase A is at 0 degrees, Phase B will be at 180 degrees. So, the voltage from (A<->B) is 240 VAC.

So, ye normal house breaker box has a bunch of breakers, horizontally oriented, stacked one on top of another. They alternate between Phase A and Phase B. So, if you want 240 VAC for the furnace or air conditioner, they gang two breakers into two slots; the two wires coming out of the two breakers are both, "hot", and the voltage between them is 240 VAC.

I've never, personally, messed with a three-phase system, but I'm sure your electrician has. I'd guess that the slots are ABCABCABC on the phases, but the electrician knows more.

Having said all that: Let's talk about power. If you're in a house and you've got a pair of 60A breakers giving you 240 VAC, then the max load with a Tesla will give you 48A. 240 VAC * 48A = Power = 11.52 kW. If, for some reason, you'd like to run 40A with a 50A breaker, then the power would be 240V * 40A = 9.6 kW.

Now, say you're in a commercial establishment. All they have is 3-phase. You can still get 48A, but the voltage for Level 2 will be 208V. With 60A breakers, the power level will be 208 * 48 = 9.98 kW. With 50A breakers, you'll get 208 * 40 = 8.32 kW.

All right. If commercial power is what you've got (and it's a condo, it might be all they've got, it's the power company that decides upon the transformer, I'm pretty sure), then 208 is in your future.

What's this do for charging times?

Consider a Model 3. It gets 250 W-hr per mile. So, the charging rates are as follows:
240 VAC @ 48A = 11.52 kW. 11.52 kW/(0.25 kW-hr/Mile) = 46 Miles/Hour
240 VAC @ 40A = 9.6 kW. 9.6 kW/(0.25 kW-hr/Mile) = 38.4 Miles/Hour
208 VAC @ 48A = 9.98 kW. 9.98 kW/(0.25 kW-hr/Mile) = 39.9 Miles/Hour
208 VAC @ 40A = 8.32 kW. 8.32 kW/(0.25 kW-hr/Mile) = 33.28 Miles/Hour.

So, suppose you got a M3 that can hold 310 miles of charge and it shows up with ten miles left on it. With 208 @ 40A it'll take it maximum time of 300/33.28 = 9 hours for a full charge to 100%; with 240 VAC at 48A it'll get to full charge at 300/46 = 6.76 hours. You'll note that both of these times come under the category of Overnight. Finally, nobody sane charges to 100% unless they've got a long trip ahead of them; usually it's 90%. And normally people don't wait until the car's dead near empty before charging: That's why you've got the charging stations in the first place. So, a more "normal" charging regime would be like, say, 200 or 150 miles, which would be three or four hours of charging.

Fine. That's how it works for a Tesla. You got a different Tesla (MY, MX, MS) they all got different W-hr/mile, it was on the sticker that came with the car.

You got other cars: Teslas max out at a current of 48A when playing with L2 AC. There are other BEVs in the world, they generally take the J1772 connector. I don't happen to know if the J1772 adapter that comes with every Tesla can handle 48A. Wikipedia claims a J1772 can do 80A, but I don't know if the adapter supports that or not.

If you want to support stuff that's not Teslas, there's charging stations/wall connectors that support J1772 at currents at or higher than 48A, but these are usually more expensive, by a hundred bucks or two, than the Tesla Wall Connector.

Frankly, I don't see that much difference between using 3-phase or 2-phase, at least in terms of time. But if it's zero cost to go for a split phase transformer from the (usual) 600VAC or 400 VAC that the power company uses as compared to a three-phase, then, what the heck, go for the split phase.

You got questions, we got answers.

Thank you for the explanation!

 

[ItsNotAboutTheMoney]

You got other cars: Teslas max out at a current of 48A when playing with L2 AC. There are other BEVs in the world, they generally take the J1772 connector. I don't happen to know if the J1772 adapter that comes with every Tesla can handle 48A. Wikipedia claims a J1772 can do 80A, but I don't know if the adapter supports that or not.

SAE J1772 Charging Adapter

Compatible with most Level 2 public charging stations, the J1772 Adapter supports charging speeds up to 19.2kW. This product comes standard with purchase of any Tesla vehicle. Includes: 1x SAE J1772 Charging Adapter Note: Compatible with all Tesla vehicles. Tesla does not regulate pricing or...

shop.tesla.com

Compatible with most Level 2 public charging stations, the J1772 Adapter supports charging speeds up to 19.2kW.

That certainly suggests 80A.

 

[Tronguy]

SAE J1772 Charging Adapter

Compatible with most Level 2 public charging stations, the J1772 Adapter supports charging speeds up to 19.2kW. This product comes standard with purchase of any Tesla vehicle. Includes: 1x SAE J1772 Charging Adapter Note: Compatible with all Tesla vehicles. Tesla does not regulate pricing or...

shop.tesla.com

That certainly suggests 80A.

19.2 kW; at 240 VAC (one option) that's 80A, all right. Question closed .

 

[RTPEV]

I've said it many many times, but you don't necessarily need to go for 48A...in most cases that will be a waste of money. However, then I saw this:

48A is probably a good idea for the first chargers if the stalls are dedicated and people are expected to move their vehicle after charging.

This is a really good point. If you anticipate that these chargers are going to be shared by multiple users and you think there is a reasonably good chance that the users will play nice and actually move their vehicles on a tight rotating schedule every couple of hours, then yes, go with a reasonably high power. Of course I'm skeptical that that would actually be the case and would more likely be used for longer durations (overnight).

In which case a 40A (or even 30A) charging station is adequate. Even 30A charging can replenish a typical day's driving 90-120 minutes and can easily give you a full charge overnight. 48A would be overkill in this kind of situation.

And because you asked in a Tesla forum, many will suggest using a Tesla Wall Connector, and I will say that the price, configurability, and functionality (with respect to load sharing, and even user billing) cannot be beat. However, you are locking out non-Tesla vehicles that don't have an adapter by going this route. Sure, the COA could provide a Tesla adapter for those vehicles, or you could require everyone to buy their own, but now you've defeated some of the advantages of the Tesla Wall Connector.

I would certainly recommend going with a 40A or even 30A J1772 unit, and it seems like the Wallbox unit you've chosen supports load sharing like the Tesla Wall Connector (something that eventually will be common in many J1772 units). There are also dual-headed units that have even more direct load sharing capability (HCS-D50 Dual Charging Station, Level 2, 240V, 25 foot cable) although I don't think the prices on those are all that great at this time.

Now, with all that said, I just checked out the price difference on the Wallbox you linked to, and the 40A is $649 and the 48A is $699. I suppose in light the the $50 difference, when the cost of the entire project including the wiring is likely to be a few thousand, the extra $100 for two 48A units vs. 40A is probably not a huge deal. Do you need it? Probably not. But it almost doesn't make sense to not buy the higher power unit for that price difference.

 

[ATPMSD]

think there is a reasonably good chance that the users will play nice and actually move their vehicles on a tight rotating schedule every couple of hours

Depending on what you install, I believe some options allow you to setup a fee schedule. Something like free to change, than a one-hour grace period, and then you get hit with idle fee charges. Might be worth looking into this as an option to add later if you find there is a need.