Power for new Chevy Volt

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pridelion

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O.k....here we go: The dealership wants me to put in two charging stations for their new Chevy Volt. Their service is 120/208 3phase. The cars can charge on 240V single phase. I need to get a 208 to 240 transformer,o.k., but.....Since the car will be charging at 240V & I will be feeding the transformer with a 2-pole breaker, can I then use a 208 to 240V single phase transformer(since the load side of the transformer will only require two phase legs for the 240V 3wire plug configuration.) I hope I explained this correctly & thank you. Let me know if I need to clarify.
 
First, see if the charger will work on 208v. If not, you can use a buck-boost instead of a full transformer, as long as the charger doesn't need a neutral.
 
pridelion said:
. . . the load side of the transformer will only require two phase legs for the 240V 3wire plug configuration.
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Would that 3-wire be two hots and a ground, or two hots and a neutral (with the ground being understood to be present, even though it is not named)? Just looking to clarify.

If you don't need a neutral, then you can do as you suggest. But Larry's suggestion would be simpler and cheaper. If you do need a neutral, then you can use a two-pole breaker to feed a 208 to 120/240 volt, single phase, step up transformer.
 
I would also ask if they think that they may have some expansion needs in the future. If so a 3 phase transformer and new panel may be a better option.
 
101021-2139 EDT

Maybe you should investigate whether GM has available 208 V 3 phase chargers that might make more sense for dealerships.

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Have they released any info on what a customer would need to charge this car in their home? I've heard that there are 120 and 240 volt chargers. Standard configuration receptacles?
 
gar said:
101021-2139 EDT

Maybe you should investigate whether GM has available 208 V 3 phase chargers that might make more sense for dealerships.

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The level III chargers are three phase, and for a good reason, they draw about 50 KW! The only car I know of that will accept that charger at this point though, is the Mitsubishi. Charges in about 30 minutes.
 
101021-2355 EDT

The following are quotes from SME Daily Briefings that I encountered when I went looking for information on GM home charging stations I had thought I had seen:
High Cost Of EV Batteries May Hamper Electric Car Ambitions.
The Wall Street Journal (10/19, Ramsey) reports efforts to make electric car viable means of transportation face a stumbling block -- the high cost of making battery packs. These costs currently account for more than half the cost of the whole car. While there are hopes that a quick takeoff in electric-car sales will result in lower battery prices, some scientists and engineers feel skeptical. Unlike some other products, they say they don't expect battery packs to reach economies of scale as manufacturers increase production, citing the price of the crucial metals used in such batteries.
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GM Executives Hope Volt Will Boost GM's Recovery.
NPR 's (10/19, Samilton) "All Things Considered" reported, "There are high expectations for [the Chevy Volt], which General Motors hopes will become America's pre-eminent green vehicle." Aaron Bragman, an IHS Automotive analyst who along with other "journalists, bloggers and analysts" drove "Volts on all-day road trips through southeast Michigan," said, "The level of technology in this thing is surprising, even to those of us who've seen high-tech cars. ... You pop the hood and it is packed." When "the internal combustion engine kicks in to power the electric motor," Bragman noted, "You barely even know the engine comes on." Because of the competition from other green-car makers, "Bragman says that means the Volt has to be perfect." And "GM executives are expressing no doubts. ... Volt marketing chief Tony DiSalle says this one car could lift the whole company."

Envision Partners With GM On Solar-Powered Charging "Trees." According to Desmond Wheatley, president of Envision Solar, "every electric vehicle is the equivalent of one or two single-family residences in terms of impact on the electric grid," the Los Angeles Times (10/19, Carpenter) "Greenspace" blog reported. "To help offset that impact, Envision has partnered with General Motors to provide solar-powered charging 'trees' to GM dealers selling its soon-to-be released Chevy Volt. ... Envision solar trees track with the sun to maximize energy production. Set up in one- and six- parking-space configurations, each space can generate enough electricity to fully charge one Volt in a day." Additionally, "the solar trees provide shade, because, Wheatley says, 80% of the electricity an electric vehicle takes on board after first plugging in goes to cooling the battery to a temperature that will accept a charge."
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The real question is how many of these cars will be sold without government incentives.

There may be some real advantage to having a large number of cars distributed around just for a floating energy reservoir. But at what cost compared with some other means?

The comment I was trying to find had a relationship on charging rate. I believe it was about 4x for the 240 unit and requires a special circuit and probably a separate meter for a cost advantage and limitation of time of use. The 120 V version can run on a 20 A circuit. Obviously technically the 240 unit could be run without a special meter. But then there is no cost advantage or ability of the government to raise the cost by adding a road energy cost that will be lost when gas stations are not the source of the vehicle fuel.

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This partical charger is rated from 95 VAC-264 VAC

• Amperage. 32Amax (Field Adjustable)
• Voltage. 95 VAC – 264 VAC
• Frequency. 50/60 Hz
• Ground Fault Trip Level. 17.5 mA (20mA Max)
• Ground Assurance. 50K ohm Max
• Operating Temperature. -35?C to +66?C
• Storage Temperature. -40?C to +85?C
• Ground Fault Test. Automatic at start-up (Firmware controlled)
• Ground Fault Retry. 4 retries @15 min. intervals (per UL 2594/UL 2231)
• Master Clear. For System Reset (Overrides Ground Fault Retry)
• Power Indication. Green LED
• Charge Status Indicators . Amber (Ready), Green (Plugged In), Green Flash (Charging) , Red Flash (Fault State)
 
Controls said:
This partical charger is rated from 95 VAC-264 VAC

? Amperage. 32Amax (Field Adjustable)
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If you do a little digging, you will find that there are 3 classes of chargers defined. The large one that the dealership wants likely loads the line to the 50kW mentioned earlier. I'm not sure if yours is the baby or the mid size ... or usable for both with the adjustable current. I _THINK_ the small works on a 120V 15A circuit, the middle on a 240V 30A circuit, and the large on 208/240/460 3 phase.
 
101022-1947 EST

Looking at several sites relating to the Chevy Volt you find that the full charge battery capacity is rated at 16 KWH. Suppose you could fully discharge this battery, and that the input energy to recharge the battery is 20 KWH. For my purposes here this will be the assumption.

It is claimed the 120 V Chevy charger can recharge this battery in 10 hours. Thus, the power input is about 2 KW and thus a current of 16.7 A. The battery won't be fully discharged when you have to recharge it. Thus, the current is probably lower.

The claim at 240 V is that charge time is less than 4 hours. The power input is about 5 KW. Thus, current is about 16.7 * 10 / ( 4 * 2 ) = 21 A. Again probably less because the battery is not fully discharged.

No AC input current was specified in any site that I looked at.

The claim is that it will cost about $1.50 to charge the battery. If that is so and they are using Detroit area electric rates, then 150/13 = 11.5 KWH at the charger input is required to charge the battery. So here is a big disparity. But that is OK if they are not talking about a fully discharged battery.

What is a gallon of gasoline worth in KWH? There are 125,000 BTU per gallon, or 125,000 / 3413 = 36.7 KWH per gallon. A gas engine vehicle may have an efficiency of 30% so from a gallon of gas we may get 11 KWH to drive the vehicle. Looks like Chevy is looking at a 30 mile range and this seems to have been a figure in the press. Our current gas prices are about $ 2.75/gallon. But these include taxes.

I doubt there is much real cost saving in operation, at least once the state figures out how to put a road tax on the electricity. But there is a tremendously higher up front cost, and higher life cycle cost.

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It's also good to realize that electric cars are not pollution-free; they merely displace it to where the electricity is generated.
 
pridelion said:
O.k....here we go: The dealership wants me to put in two charging stations for their new Chevy Volt. Their service is 120/208 3phase. The cars can charge on 240V single phase. I need to get a 208 to 240 transformer,o.k., but.....Since the car will be charging at 240V & I will be feeding the transformer with a 2-pole breaker, can I then use a 208 to 240V single phase transformer(since the load side of the transformer will only require two phase legs for the 240V 3wire plug configuration.) I hope I explained this correctly & thank you. Let me know if I need to clarify.
Click to expand...

This might help..http://en.wikipedia.org/wiki/Chevrolet_Volt
http://www.examiner.com/gm-in-national/recharge-the-chevrolet-volt-four-hours
 
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People also need to consider that if the electric vehicles were to suddenly become popular - that the power grid may not handle the increase in load in some areas that already are pushed to the limit at times.
 
LarryFine said:
It's also good to realize that electric cars are not pollution-free; they merely displace it to where the electricity is generated.
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And in some areas that'll mean replacing fairly clean burning gas engines with (mostly) coal generation, a large step backwards.

Back on topic, the EV chargers are clever bits of electronics, and tehre should be a model available that doesn't involve fitting a customer owned (and heated) transformer.
 
GeorgeB said:
If you do a little digging, you will find that there are 3 classes of chargers defined. The large one that the dealership wants likely loads the line to the 50kW mentioned earlier. I'm not sure if yours is the baby or the mid size ... or usable for both with the adjustable current. I _THINK_ the small works on a 120V 15A circuit, the middle on a 240V 30A circuit, and the large on 208/240/460 3 phase.
Click to expand...

My point and understanding was ( I could be wrong) :OP is concern about using 208V instead of 240V . OP mentioned that dealer's service is 120/208V 3 Ph. I was just trying to point out the voltage range in some of the chargers out there being,from 94V-264V single phase. Of course, none of us know exactly what he is asked to install.Mine was just an example. I do not have to do any digging
 
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