277V Charging

[Mach-Lee]

Curious if anyone has tried this or not. The max listed AC charging voltage is 280V, so in theory the car should charge off 277V as long as the voltage doesn't fluctuate much higher. There is likely a power cap on the charger at 11.5 kW so 277V wouldn't necessarily charger faster than 240V.

277V is the L-N voltage of a 480V 3-phase power system found in some commercial locations. Support for 277V charging is desirable since it makes the installation of an EV charger at these locations much simpler and cheaper vs. having to install a costly step-down transformer. I think 277V support is important for helping charging infrastructure grow in an economical way at locations that otherwise don't have 208 or 240V.

Most Teslas support 277V charging for comparison, some better than others. Some people may encounter 277V at certain Tesla destination chargers.

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[ABMust]

Curious if anyone has tried this or not. The max listed AC charging voltage is 280V, so in theory the car should charge off 277V as long as the voltage doesn't fluctuate much higher. There is likely a power cap on the charger at 11.5 kW so 277V wouldn't necessarily charger faster than 240V.

277V is the L-N voltage of a 480V 3-phase power system found in some commercial locations. Support for 277V charging is desirable since it makes the installation of an EV charger at these locations much simpler and cheaper vs. having to install a costly step-down transformer. I think 277V support is important for helping charging infrastructure grow in an economical way at locations that otherwise don't have 208 or 240V.

Most Teslas support 277V charging for comparison, some better than others. Some people may encounter 277V at certain Tesla destination chargers.

So where did you see that the Maximum is 280V . ive been looking that from the manual but no luck.
i had been using a tesla to J1772 adapter to charge my 2022 Mach E Premium Extended at work . After 7 months of using it i started getting charge station at fault. i change 2 diff adapters now. im ordering a tesla tap 80AMP 250V i will give it a try again in my work location. lets see if i will get a charge station at fault.

 

[AKgrampy]

Well if 280V were the max that would be an issue. Some utilities run their voltages near the substation “hot” so that the voltage does not dip too much at the end of a feeder. So electrical services near the substation may have voltages slightly over 277V.

 

[Mach-Lee]

So where did you see that the Maximum is 280V

Service manual.

Well if 280V were the max that would be an issue. Some utilities run their voltages near the substation “hot” so that the voltage does not dip too much at the end of a feeder. So electrical services near the substation may have voltages slightly over 277V.

Yup, 280V is only 1% over spec, so easy to go over if using 277V. Usually you need ±5% tolerance minimum. The input capacitors are probably only rated for 400VDC which you'd be very close to with rectified 280VAC. Bumping up to 450V caps in the charger would be required to fully support 277V charging, which would add a slight additional cost.

 

[Hammered]

Service manual.



Yup, 280V is only 1% over spec, so easy to go over if using 277V. Usually you need ±5% tolerance minimum. The input capacitors are probably only rated for 400VDC which you'd be very close to with rectified 280VAC. Bumping up to 450V caps in the charger would be required to fully support 277V charging, which would add a slight additional cost.

I've got a 280v DC supply -- Think it will eat it?

 

[ABMust]

Did you guys having issue using Tesla destination charger 60amp 277V ? After 7 months of charging at work using Tesla to my Mach e using adapter suddenly I have this charge station at fault . I don’t know if it’s the adapter . I bought a Tesla tap 80amp 250v and it will be here tomorrow . Hope this will work

 

[ATL]

I've got a 280v DC supply -- Think it will eat it?

Well, it would depend on whether that 480 V "spec" were a maximum allowable or a nominal, in which case the tolerance of 5% should be on top of that. It is potentially a pretty expensive test to run!

Wouldn't it be nice if some of the Ford engineers had the latitude to respond to the more technical questions in this forum... To everyone's benefit. It's basically a very straightforward question, with the possibility of a clear answer.

 

[Hammered]

Well, it would depend on whether that 480 V "spec" were a maximum allowable or a nominal, in which case the tolerance of 5% should be on top of that. It is potentially a pretty expensive test to run!

Wouldn't it be nice if some of the Ford engineers had the latitude to respond to the more technical questions in this forum... To everyone's benefit. It's basically a very straightforward question, with the possibility of a clear answer.

I've run other devices on DC. Anything that rectifies AC into DC should in theory be able to use similar DC voltage -- results not guaranteed of course.

 

[ATL]

I've run other devices on DC. Anything that rectifies AC into DC should in theory be able to use similar DC voltage -- results not guaranteed of course.

I think we are a little misaligned in our comments. The 480 and 277 V numbers are AC. I probably should have said 277 V instead of 480 because all I meant was that if the Mach-E spec says it will accept 280 VAC, then it might be ok with a normal tolerance of 5% above that amount, should the 277 VAC be operating at the top of its tolerance level. My bad if I created confusion. I habitually use phase-phase voltages instead of phase-neutral voltages when discussing 3-phase systems. Not everyone does that.

Agreed that DC voltages are independent.

I'll add that here in Canada, we use 600 VAC as the common utilization standard for small industrial and commercial systems, though some plants that source US manufactured equipment do use 480 V. The typical 347 volt P-N voltage here is not useful at all for this discussion as originated by M-L.

 

[ABMust]

So to make this very simple the answer is YES ? you can charge your mustang mach e using the TESLA DESTINATION CHARGER (AT WORK) 60 AMP, 277VAC. USING THE TESLA TAP TO J1172 WITH 80AMP, 250VAC ADAPTER. LETS LAND THE PLANE . ITS JUST A YES OR NO.

 

[ATL]

So to make this very simple the answer is YES ? you can charge your mustang mach e using the TESLA DESTINATION CHARGER (AT WORK) 60 AMP, 277VAC. USING THE TESLA TAP TO J1172 WITH 80AMP, 250VAC ADAPTER. LETS LAND THE PLANE . ITS JUST A YES OR NO.

Not really...
You previously used a 277 VAC Tesla destination EVSE with your MME successfully without damaging the car or getting any fault indications on the MME? If true, then you have demonstrated that it can work.

Subsequently charging failed for some reason, still undetermined. So you can try all the adapters in existence and if it works, great. Doesn't sound like a car or built-in charger issue.

You are stressing those adapters a bit, it would seem, operating then at 277V (our perhaps even a little higher as previously noted) when they are rated at 250 VAC. Perhaps that's the source of the failure.

This whole thing seems experimental. Any EVSE just passes through what it's supplied with. As long as the connected equipment works, then great. As Mach-Lee noted in his OP, it would improve the numbers of locations that companies can provide additional charging connections at reasonable cost to them. Manufacturers should endorse this so we'd all know it's ok and won't hurt our vehicles. That would be the yes that your looking for.

 

[kkmoon]

I don't have charging at work, but the parking lot lights are wired to 277V. What are the odds that the circuit has the capacity to add an EVSE...

Probably pretty close to zero is my guess.

 

[Mach-Lee]

I don't have charging at work, but the parking lot lights are wired to 277V. What are the odds that the circuit has the capacity to add an EVSE...

Probably pretty close to zero is my guess.

Pretty good during daylight hours since there’s no load. It would require additional controls to implement safely but the wires and circuit capacity are there. You might even be able to charge at night if the installation was originally for halogen or halide bulbs and was converted to LED fixtures. Because LEDs use up to 70% less power, the lighting circuit now has unused capacity that could be utilized for EV charging.

 

[kkmoon]

Pretty good during daylight hours since there’s no load. It would require additional controls to implement safely but the wires and circuit capacity are there. You might even be able to charge at night if the installation was originally for halogen or halide bulbs and was converted to LED fixtures. Because LEDs use up to 70% less power, the lighting circuit now has unused capacity that could be utilized for EV charging.

Interesting. That's exactly what it was, old metal-halide replaced with LED a couple years ago. We have an electrician coming out in a couple days for some unrelated work. I will see what he thinks.

Do you think any EVSE designed for 240V could plug into 277V?

 

[Mach-Lee]

Interesting. That's exactly what it was, old metal-halide replaced with LED a couple years ago. We have an electrician coming out in a couple days for some unrelated work. I will see what he thinks.

Do you think any EVSE designed for 240V could plug into 277V?

Finding an EVSE that works could be an issue. I think the older Tesla one was the only one I know of that was designed to work with 277V. Not sure if the new Tesla J1772 would work or not. If you use a 240V EVSE it’s a dice roll whether it would work or not. You might have to make some calls.

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