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Who needs a Super charger when you can have a GIGA charger! LOL
- Thread starter Notyourdad
- Start date
Haven't seen too much information on the version 3 charger but a new one by me in the Buffalo area (Cheektowaga Supercharger on Plugshare) prompted this email to a friend recently:
Just for a bit of background, Tesla chargers (typically in parking lots) work by getting the VIN of the Tesla charging, and then bill the owner's credit card on file, prior to energizing.
The model used for the first 7 years were 12 '10 kw' car chargers (same as used in the 2013 MODEL S sedan), giving an optimistic 120 kw to charge the car. These were put in 3R rack cabinets along with glycol coolers (as would be used in the car), and provide the rated power at 250 volts and above. Since here, they ran on 277 volts they were used at full power - but a typical installation (at Eastern Hills mall in Clarence) of 8 parking spots would be run by 4 of these rack cabinets - hence they were numbered 1A,1B..... etc on to 4B. To get maximum power, cars would arrive and park somewhere where they were the only car of the same # (the mate parking spot preferably being empty) so that way their cars wouldn't have to 'share' the 120 kw charger with another car.
The most recent incantation of this (so called 'version 3' - I don't know what v2 was), has a much larger convection cooled block (about 3 times the size of the old fan cooled rack cabinets) with the output going to 4 parking spots - in other words, this Cheektowaga location (only a few miles from Eastern Hills) in the Panara Bread parking lot across from Galleria is also 8 stalls but in this case the labeling is 1A, 1B, 1C, 1D for the first charger up to the last parking spot being 2D, with only 2 charger blocks instead of the 4 rack cabinets as at Clarence. So here, a Model 3 vehicle (currently the only Tesla that can go at 250 kw (for 5 minutes) ) would optimally have the other 3 parking spots vacant as to get the full power from the charger for itself.
I took pictures, but they are too large for YAHOO to accept the upload. Incidentally, this was a very low cost installation. Gone is the typical Square-D 3 bay wide QED-2 switchgear (Hollywood Theatre had a ONE-Bay QED-2 to show you how massive 3 must be), and just have 2 - 600 amp mains in separate 3R breaker enclosures - somewhat larger (about 5X) than the one on the back of your house. Each fed (no doubt) by 3- 2-1/2" SCHED 80 pipes with 4-4/0 AL XHHW inside. These are mounted on unistrut with 6 plastic 2-1/2" pvc80 plus expansion sliders going into the ground (3 in, 3 out to the huge charger block, and then the whole thing duplicated. In other words there is no overall main. Just 2 cheap 600 A breakers, in separate enclosures each going to its individual charger block, and then out to 1-4 or 5-8 car charging stalls. Revenue metering is handled by an ESTER type 9S meter (meter multiplier 750 - Nyseg does *NOT* put 277 on the meter (unlike National Grid)- , but only 110.8 volts as inside the 750 kva (coincidence) pad transformer (which the revenue meter is bolted to) are 3 - 2.5:1 voltage transformers and 3- 1500:5 current transformers so 2.5 * 300 = 750 hence the meter multiplier. Both Nyseg and NG use 'high voltage drop' 5.87% impedance transformers that sacrifice tight voltage regulation for minimal fault current available. In this case a 750 kva pad has a full load current rating of 902.5 amperes, and a fault current of a leisurely 15,478 amperes. So, the cheap 600 ampere mains (one of two in this case) only have to have an 18,000 ampere interrupting rating. There is a 3rd 'single phase' 277/480 volt 30 ampere service running to a 3R - Square D double pole 30 amp safety switch which goes to a 'tesla box' which presumably handles the cell-phone call to the data base, and (I'm guessing here) can remote trip the 2 main breakers 'over the phone' should somebody report a fire or explosion. The 3R enclosures for the 600 amp breakers are left unlocked, so this is the FIRST Tesla supercharger installation I've ever seen world-wide that had a 'readily accessible disconnect' - something NEC has ALWAYS required for over 60 amperes or over 150 volts to ground. In Norway, a Tesla Model S burned down to absolutely nothing when a defective car could not be shut down from charging.... None of the supercharger installations had so much as an emergency stop button, something ALL GAS STATIONS have had for decades. Since the car is aluminum, it all goes up in flames once you get it hot enough.
So curiously, this is the first Supercharger installation ever that I've heard about where the Inspector hasn't had to have been bribed.
Here's the charger ratings:
Continuous AC rating : 350 kva @ 480 vAC.
Input: 360-528 vac 3ph (allows anything from 380 in europe to 480 plus 10% in the states)
430 amperes maximum continuous rating, (my interpolated current draw is 421 amperes at 480 volts for 350 kva), however the output from the pad transformer will be around 452 volts due to the 5.87% impedance drop - I don't know if the primary 7200Y/12470 is 'high' in that area or not. Its close but not the same as NG's 13,200 volts.
Individual PORT output availability: (1 of 4): 250 kw maximum per port, 0-500 VDC, 631 amperes max (250 kw interpolated by me would be 396 volts).
coconutboy84
Member
Yes, also TLDR mostly, but in skimming over, this funny malapropism caught my eye:
It sometimes does feel like some of these sites could use some magic to get them finished.
eprosenx
Active Member
Awesome writeup!
I assume you are a power systems engineer?
FWIW, I think V1 vs V2 superchargers are slightly different. I think V1 was based around the tech that drove the original 40kw chargers in the original model S, and the V2 was based on the newer chargers in the S and X current models. One big difference is that the newer ones would not handle the higher voltages (they would error out) and so Tesla had to go back and retrofit a bunch of “buck” transformers into a bunch of supercharging stations since the utility voltage might vary at times. They also stopped supporting 277v to Wall Connectors because of this.
I am told that Model 3’s chargers have no such issue with 277v +10%.
I kind of want to put a 277v Wall Connector at work just for funsies...
smatthew
Active Member
Nope. The charger sees "Supercharge Enabled" and supercharges. The car reports the energy used to Tesla, and the amount is added to your bill. No credit card is billed prior to energizing.
Not necessary with v3 chargers. The limit with v3 chargers is the size of the transformer. Even at locations without the transformer capacity to deliver 1000 kWh, charging won't be restricted unless four cars show up at exactly the same moment at very low states of charge.
That's a serious accusation. You're claiming Tesla has bribed inspectors in every state of the USA?
We noticed.
smatthew
Active Member
eprosenx
Active Member
I really appreciate @Bill25cycle 's post. There might be a couple of tweaks to correct the record, but I find the info / insight really valuable.
Yeah, I have heard this is how it works as well. But conceptually you just plug in and it charges your car. Never mind how the sausage is made. ;-)
(I will say though, that in the long run this architecture is questionable - folks will find ways to steal things - crypto certificates for vehicle authentication for billing purposes and protocols to handle it all will become critical)
So I am very curious to learn the limitations of the V3 chargers. Bill's post is helpful in understanding what they might be. Are we saying that a single cabinet can handle four cars at 250kW simultaneously? A full megawatt in one cabinet? I highly doubt it. More likely than the transformer being the limit (since they are likely 1.5 or 2.5 MVA) is that the feed conductors from the switchgear can't feed that and likely the rectifiers in the V3 supercharger can't do it either (or its cooling). The V3 superchargers probably have some limit just like V2, but it is so much higher that Tesla figures it will virtually never be hit due to the connected cars being at the wrong state of charge, cold battery, etc...
Also, you can abuse the crud out of transformers for short periods of time. ;-) The utility commonly runs their transformers at way over rated load. So the transformer is not the item I would peg as usually being the limitation (though also, the utility may limit Tesla to a given anmount of service capacity at a location due to loading on their feeder system even if the transformer is sufficient).
I think his callout is a valid one in that by the NEC they do call for readily accessible disconnect in Article 625, however, a supercharger is a special situation under engineering supervision and so I extremely doubt any bribes were paid (and actually, I wonder if DC Fast Charging is even covered in Article 625? - I may have to go back and re-read it). Exceptions to code are often made when there are extenuating circumstances (like vandalism would be a massive issue, there are lots of folks who I am sure love to "roll coal" that would just go around hitting the emergency shutoff button). Gas stations usually have staffing in case someone maliciously hits the shutoff button.
Yeah, I have heard this is how it works as well. But conceptually you just plug in and it charges your car. Never mind how the sausage is made. ;-)
(I will say though, that in the long run this architecture is questionable - folks will find ways to steal things - crypto certificates for vehicle authentication for billing purposes and protocols to handle it all will become critical)
So I am very curious to learn the limitations of the V3 chargers. Bill's post is helpful in understanding what they might be. Are we saying that a single cabinet can handle four cars at 250kW simultaneously? A full megawatt in one cabinet? I highly doubt it. More likely than the transformer being the limit (since they are likely 1.5 or 2.5 MVA) is that the feed conductors from the switchgear can't feed that and likely the rectifiers in the V3 supercharger can't do it either (or its cooling). The V3 superchargers probably have some limit just like V2, but it is so much higher that Tesla figures it will virtually never be hit due to the connected cars being at the wrong state of charge, cold battery, etc...
Also, you can abuse the crud out of transformers for short periods of time. ;-) The utility commonly runs their transformers at way over rated load. So the transformer is not the item I would peg as usually being the limitation (though also, the utility may limit Tesla to a given anmount of service capacity at a location due to loading on their feeder system even if the transformer is sufficient).
I think his callout is a valid one in that by the NEC they do call for readily accessible disconnect in Article 625, however, a supercharger is a special situation under engineering supervision and so I extremely doubt any bribes were paid (and actually, I wonder if DC Fast Charging is even covered in Article 625? - I may have to go back and re-read it). Exceptions to code are often made when there are extenuating circumstances (like vandalism would be a massive issue, there are lots of folks who I am sure love to "roll coal" that would just go around hitting the emergency shutoff button). Gas stations usually have staffing in case someone maliciously hits the shutoff button.
smatthew
Active Member
Most supercharger installations have a 500-1,000 kva transformer for 8 stalls. LV Linq is an exception with a 2500kVA for 16 spots (I believe).
Tesla says the equipment in the cabinet is rated for 1MW of charging.
The label on the equipment seem to indicate more like sub 600kW of charging.
So, if you're the 4th car, you might be throttled. Should be better than the current situation. Personally, it's infuriating when this happens to me: There's a line at the supercharger. A slot opens up, you pull in, and because the other car has priority, you get 30kW charge rate. Then the next spot opens up, and the driver pulls in and gets 90+ kW charge rate because they're paired with someone who is using a supercharger to fill up to 100%
Awesome writeup!
I assume you are a power systems engineer?
FWIW, I think V1 vs V2 superchargers are slightly different. I think V1 was based around the tech that drove the original 40kw chargers in the original model S, and the V2 was based on the newer chargers in the S and X current models. One big difference is that the newer ones would not handle the higher voltages (they would error out) and so Tesla had to go back and retrofit a bunch of “buck” transformers into a bunch of supercharging stations since the utility voltage might vary at times. They also stopped supporting 277v to Wall Connectors because of this.
I am told that Model 3’s chargers have no such issue with 277v +10%.
I kind of want to put a 277v Wall Connector at work just for funsies...
Oh, ok great! Your explanation explained why they first allowed 277, and then, didn't!
Oh that's just silly. While I don't know precisely the mechanism for billing the customer, there is communication with a Tesla database that provides billing information. The more serious error on my part is what the 'TESLA BOX' does on the 'Service Entrance Unistrut'. Apparently if the car 'handles' the billing, then the former is strictly for management of the charger boxes.
Another big error you made is saying 1000 kw is possible, when the NAMEPLATE INFORMATION I listed on the charger clearly says the output is 250 kw per port WITH THE PROVISO that continuous draw is limited to 350 kva.
I would assume Tesla is providing more accurate information on their nameplates than you are with your 'commentary'.
Another thing: Get familiar with NEC code requirements for the past few decades before lodging a complaint.
Eprosenx:
Hi!
Smathew is apparently correct as to the billing mechanism - I stand corrected on that point, but his electrical explanations don't make any sense. The inspection issue may be that - prior to being 'corraled' the disconnects were readily accessible.
Problem is, after the inspector left they put a stockade fence around the v1 charger / switchgear complex, and put a padlock on the whole thing, making it inaccessible.
As regards the charger ultimate draw, the Nameplate info on the Charger clearly states it is rated for 350 kva @ 480 volts.
Since the nameplate says the allowable input voltage is 360-528 volts it looks like a 'clean sheet' design and doesn't bother with 240-277 any longer. In this 8 stall installation - there were 2 - 600 ampere breakers (1 per charger block), with no overall main - the Breakers themselves being a 'multi-main'. Very low cost. This particular Utility (New York State Electric and Gas) allows all kinds of customer friendly designs (in this case 3 service disconnects: 2 - 3 pole 600 amp breakers, and 1 - 2 pole 30 amp fusible switch).
The neighboring Utility a few miles away (National Grid) is much more fussy. But these 2 supercharger installations - each 8 stalls, with Eastern Hills being V1, and Cheektowaga being V3, are both in NYSEG territory.
Canadian installations will quite obviously still require autotransformers to provide the derived 480 from their 347Y/600 supplies.
Hi!
Smathew is apparently correct as to the billing mechanism - I stand corrected on that point, but his electrical explanations don't make any sense. The inspection issue may be that - prior to being 'corraled' the disconnects were readily accessible.
Problem is, after the inspector left they put a stockade fence around the v1 charger / switchgear complex, and put a padlock on the whole thing, making it inaccessible.
As regards the charger ultimate draw, the Nameplate info on the Charger clearly states it is rated for 350 kva @ 480 volts.
Since the nameplate says the allowable input voltage is 360-528 volts it looks like a 'clean sheet' design and doesn't bother with 240-277 any longer. In this 8 stall installation - there were 2 - 600 ampere breakers (1 per charger block), with no overall main - the Breakers themselves being a 'multi-main'. Very low cost. This particular Utility (New York State Electric and Gas) allows all kinds of customer friendly designs (in this case 3 service disconnects: 2 - 3 pole 600 amp breakers, and 1 - 2 pole 30 amp fusible switch).
The neighboring Utility a few miles away (National Grid) is much more fussy. But these 2 supercharger installations - each 8 stalls, with Eastern Hills being V1, and Cheektowaga being V3, are both in NYSEG territory.
Canadian installations will quite obviously still require autotransformers to provide the derived 480 from their 347Y/600 supplies.
Last edited:
Smathew said:
"....Not necessary with v3 chargers. The limit with v3 chargers is the size of the transformer. Even at locations without the transformer capacity to deliver 1000 kWh, charging won't be restricted unless four cars show up at exactly the same moment at very low states of charge...".
Oh boy, another self-appointed Big Expert.
Chief: 1000 kw at 480 volts is around 1,204 amperes, and that assumes the fantasy of 100% efficiency and 100% Power factor.
Assuming the efficiency is slightly less than 100%, 1300 amperes on a 600 ampere circuit breaker (especially an '80% rated' one) will tend to nuisance trip it.
A 600 ampere circuit breaker is just ducky for a Continuous Load where the maximum continuous load PER THE TESLA NAMEPLATE is 350 kva; around 422 amperes at 480 volts, or 447 amperes at the more likely expected 452 volts, as I explained in my original letter to my friend.
"....Not necessary with v3 chargers. The limit with v3 chargers is the size of the transformer. Even at locations without the transformer capacity to deliver 1000 kWh, charging won't be restricted unless four cars show up at exactly the same moment at very low states of charge...".
Oh boy, another self-appointed Big Expert.
Chief: 1000 kw at 480 volts is around 1,204 amperes, and that assumes the fantasy of 100% efficiency and 100% Power factor.
Assuming the efficiency is slightly less than 100%, 1300 amperes on a 600 ampere circuit breaker (especially an '80% rated' one) will tend to nuisance trip it.
A 600 ampere circuit breaker is just ducky for a Continuous Load where the maximum continuous load PER THE TESLA NAMEPLATE is 350 kva; around 422 amperes at 480 volts, or 447 amperes at the more likely expected 452 volts, as I explained in my original letter to my friend.
Turlejay
Member
I'm in the Buffalo area too and haven't stopped over there yet either. Anyone who's posted said they haven't gotten that v3 speed yet
smatthew
Active Member
I never said the charger could handle 1000kW. I said "unless four cars show up at exactly the same moment at very low states of charge" you won't be restricted.
Which clearly indicates that 1000kW is not possible.
The 250kW charge rate drops rather quickly. At best, you start at 5% and have the 250kW rate for 15% of the charge. Let's see - 15% of 75kWh = 11.25 kW. At 250 kW, you charge at max rate for 2.7 minutes. Then it's 10 minutes to add an additional 40%/30kWh to get to 60% where you are drawing 110kW. See how quickly it drops off? The last 30% of the charge (22.5kWh) takes 18 minutes, as your charge rate evenly declines to 40kW
Unless Model 3 LR show up at 5% SOC faster than every 8 minutes, the charger can handle it.
You're more likely to be limited by a V3 charger that isn't working properly, than an actual charging load.
eprosenx
Active Member
Here is a past thread I started on 277v specifically: Info from Tesla - 277v feed to Wall Connector (HPWC) - Which Cars Support It
FWIW, I am pretty sure each rectifier module in the new V3 superchargers is still 277v since they have a neutral in all the feed conduits from the main switchgear.
Check out the nameplate one the new one at Vancouver Mall in Washington:
I have not seen anyone else talk about how fascinating the DC Input / Output section is! Clearly to me this is intended either for multiple cabinets to load share with each other (if one has four cars all demanding super high charge rates), or perhaps more likely it is intended for Tesla Batteries (Which could both help with the surge load need for hungry cars and also help reduce demand charges, time shift energy charges, make better use of renewables, etc...). Up to 640 amps and 1000 volts!!!
I can't wait to try one!
640k
Member
No indication of this charger (made in Buffalo, incidentally) uses 277 as there is nothing on the nameplate regarding that. It says the input is '480' with an allowable range of 360-528 volts, 50/60 HZ. Good for Europe or the States. Since this is not used in the home there'd be no reason for it, and other reasonably high power rectifiers rarely have the neutral connection, whether 208, 480, or 600 volts.
The old 40 ampere chargers can take a lower voltage (277 nominal maximum) only, and are single-phase only. Whereas this unit is obviously designed expressly for Supercharger service, and single-phase operation at a low or high voltage is unnecessary.
Whether internally this is a 3 phase, or like Porsche, a 6 phase unit; is unspecified, but the neutral isn't necessary in any case as the loading on the phases is balanced.
Forcing a job for a neutral is a bit silly, as its much less parts to just use the 3 phase input as-is and not use multiple single phase powered supplies. The only downside comparing this nameplate with a v1 nameplate is this unit cannot be used on 240 volts as the v1 models could have been. But then so few were that it surely wasn't a design constraint and hence 360 volts is the lowest operating voltage of this unit.
Electricians typically send 4 wires in the conduit, which is incidentally required here as one of the wires is needed for the equipment grounding conductor as plastic pipe is non-conductive. If you see 5 wires, then it is because they do it out of force of habit. I've seen many pieces of equipment where the neutral wire is uncommitted just because somebody thought they'd need it.
Rather like the Nema 14-50R (4 prong) in people's garages. The neutral is rarely used. Tesla gets most of the credit for 'standardizing' the 'Recreational Vehicle' connection - as at least half the other companies are using this as opposed to a 6-50R (3 prong).
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