Ford Charge Station Pro Wiring Requirements (A/L1 and B/N)

[Labs4Lightning]

You can run aluminum and transition to copper in a junction box near the EVSE.

Don’t have charger yet, but what I’m doing.

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[Maquis]

He agrees, that is one possibility. He thinks (mostly due to minimum purchase amounts) that the added cost of the junction box and labor almost negates the cost savings, though. So I'm probably going with copper.

I do wish shopping for a competent electrician was easier.

Maybe there’s something more complicated about your installation, but a $5 4-square box and an extra 30 minutes labor should be less expensive than copper wire for are run of any significant distance.

 

[FlasherZ]

If that’s actual measured voltage, it’s pretty low.

It's low, but in line with the US's long history of randomness in electrical systems.

In the northeast, it's not uncommon to find 220V systems around (110V), in fact you'll find on this very forum a lot of people talking about "220". "220, 221, whatever it takes..."

I'm surprised to see it in Hartford, WI (the poster's location listed) but it can also be for many other reasons. My home is 248V, because I'm only a couple of miles from a substation that needs to feed very long runs out to rural farms, where voltage needs to be kept up to minimum specs at the end. For a while, they had it up to 252 and my protection gear started kicking in.

It is, indeed, low, and that means longer charging times for someone at 220V vs. 240V (about 8% less power, so that much longer).

 

[Maquis]

It's low, but in line with the US's long history of randomness in electrical systems.

In the northeast, it's not uncommon to find 220V systems around (110V), in fact you'll find on this very forum a lot of people talking about "220". "220, 221, whatever it takes..."

I'm surprised to see it in Hartford, WI (the poster's location listed) but it can also be for many other reasons. My home is 248V, because I'm only a couple of miles from a substation that needs to feed very long runs out to rural farms, where voltage needs to be kept up to minimum specs at the end. For a while, they had it up to 252 and my protection gear started kicking in.

It is, indeed, low, and that means longer charging times for someone at 220V vs. 240V (about 8% less power, so that much longer).

ANSI C84.1 dictates voltage tolerances. Many utilities seem to ignore this. When the first Mach-Es were delivered, there were a lot of people in the Chicago area who couldn’t charge because their utility voltage was way too high - 258-260V. ComEd basically told them to pound sand so Ford provided a software update to accept the higher voltages.

 

[FlasherZ]

ANSI C84.1 dictates voltage tolerances. Many utilities seem to ignore this. When the first Mach-Es were delivered, there were a lot of people in the Chicago area who couldn’t charge because their utility voltage was way too high - 258-260V. ComEd basically told them to pound sand so Ford provided a software update to accept the higher voltages.

Sure, but many of these grids pre-date ANSI standards (which are +/- 5% of 240VAC RMS, or 228V-252V for those not familiar with the standard) and I don't see ANSI stepping up to fund rebuilds of chunks of the grid where 220V was the original voltage and will likely be for a very long time.

Not sure of the chargers used in the Ford, but the chargers in the Tesla use switching power supplies and have ratings of 85-265V, so seems ok that they'd up the software if it's found to be ok.

Tesla cars will accept higher voltages but will clip the amperage so that the power limit is not exceeded. For example, my car which allows for 72A at 240V will only charge at up to 69A at 250V to stay below the 17.28 kW power level. IMO, that's way too conservative because the charger electronics are built around current and not small variations in voltage, but it is what it is.

 

[Maquis]

Sure, but many of these grids pre-date ANSI standards (which are +/- 5% of 240VAC RMS, or 228V-252V for those not familiar with the standard) and I don't see ANSI stepping up to fund rebuilds of chunks of the grid where 220V was the original voltage and will likely be for a very long time.

Not sure of the chargers used in the Ford, but the chargers in the Tesla use switching power supplies and have ratings of 85-265V, so seems ok that they'd up the software if it's found to be ok.

Tesla cars will accept higher voltages but will clip the amperage so that the power limit is not exceeded. For example, my car which allows for 72A at 240V will only charge at up to 69A at 250V to stay below the 17.28 kW power level. IMO, that's way too conservative because the charger electronics are built around current and not small variations in voltage, but it is what it is.

Good point about the historical aspect of compliance - I hadn’t thought about that.

I’d bet the MME also uses a switching power supply, but I don’t know for sure.

 

[SteffanG]

Maybe there’s something more complicated about your installation, but a $5 4-square box and an extra 30 minutes labor should be less expensive than copper wire for are run of any significant distance.

It would more likely be a 8x8 junction box plus lugs for the wires and 2 extra connectors so about $80-$100 in parts. It would likely be closer to an hour labor once you factor in putting everything in, drilling the holes, making the connections, ect.
Also don't forget to carry the same current aluminum wire is a larger size (not sure exactly as I dont have a table in front of me and rarely deal with larger sizes). Anything less than about a 50' run would end up costing more.

Ford likely doesn't make the power supply. It is probably from Siemens like the pro wall charger. They wouldn't redesign a power supply so would likely use an off-the-shelf switching power supply to keep costs and R&D lower.

 

[FlasherZ]

Also don't forget to carry the same current aluminum wire is a larger size (not sure exactly as I dont have a table in front of me and rarely deal with larger sizes). Anything less than about a 50' run would end up costing more.

My experience has been that there isn't that much difference between the two. There is *some* savings in using AL for long runs, but it's really not that much and the junction is rather ugly IMO, along with more things to go wrong. The AL/CU lugs (probably Polaris connectors) are $20 ea. at my price.

80A charging requires #1 AL or #3 CU @ 75 degC, about $1.30/ft for #1 AL, $2.30/ft for #3 copper. Difference for 100 ft. run would be about $300 in wire, minus the junction box, polaris connectors, and a bit of extra labor... you won't save much (maybe $100-200 at best).

Ford likely doesn't make the power supply. It is probably from Siemens like the pro wall charger. They wouldn't redesign a power supply so would likely use an off-the-shelf switching power supply to keep costs and R&D lower.

The power supply is in the vehicle charger itself, and will be a switching supply - I can guarantee there won't be a linear supply in a truck charger. The question is just for how much of a range was the power circuitry designed? I have seen people run Tesla's internal chargers at 277VAC (L1-N on a 480VAC Wye 3ph system), but it violates warranty (and if I recall correctly, the circuitry in the wall connector went poof in relatively short order).

 

[Amps]

On a 100 foot run, I'd splurge and add a disconnect for the EVSE if it's that far from the panel.

 

[tls]

It would more likely be a 8x8 junction box plus lugs for the wires and 2 extra connectors so about $80-$100 in parts. It would likely be closer to an hour labor once you factor in putting everything in, drilling the holes, making the connections, ect.
Also don't forget to carry the same current aluminum wire is a larger size (not sure exactly as I dont have a table in front of me and rarely deal with larger sizes). Anything less than about a 50' run would end up costing more..

You end up with something like this, though, note, this is all #3 copper in this box - the Al will be bigger, stiffer, generally less pleasant to deal with. Once you put 3 big Polaris connectors in there there will not be a ton of space left (sorry, I didn't take another shot before buttoning this back up). On the other hand you will have one gozinda and one gozowda rather than two gozowdas and a signal cable as you'll see here. You can get it in a 6x6 box with the Polarises but you won't be able to leave much slack for any future revisions, so you may curse yourself for not going 8x8 later.

 

[Maquis]

You end up with something like this, though, note, this is all #3 copper in this box - the Al will be bigger, stiffer, generally less pleasant to deal with. Once you put 3 big Polaris connectors in there there will not be a ton of space left (sorry, I didn't take another shot before buttoning this back up). On the other hand you will have one gozinda and one gozowda rather than two gozowdas and a signal cable as you'll see here. You can get it in a 6x6 box with the Polarises but you won't be able to leave much slack for any future revisions, so you may curse yourself for not going 8x8 later.

Junction boxes are sized based on conduit size. NEC basically requires the dimension to be a minimum of 8 X the conduit trade size, so 1” pipe means 8” minimum.

Electricians I know all consider aluminum wire to be easier to work with (lighter and more flexible) than copper of equivalent ampacity. Of course that can be mitigated if using aluminum ends up needing bigger pipe. The cost advantage of aluminum has diminished in the last 2 months as copper prices have dropped while aluminum has held fairly steady.

The NEC does not permit 2 EVSEs on one branch circuit as shown in your picture.

 

[FlasherZ]

The NEC does not permit 2 EVSEs on one branch circuit as shown in your picture.

If they are part of a listed load-sharing system and coordinate their load management together (as the two pictured units do), then it is permitted. It's not so much "an EVSE", but rather just "EVSE" ("Electric Vehicle Supply Equipment").

 

[Maquis]

If they are part of a listed load-sharing system and coordinate their load management together (as the two pictured units do), then it is permitted. It's not so much "an EVSE", but rather just "EVSE" ("Electric Vehicle Supply Equipment").

I know that the listed load management feature allows reducing the feeder size and the load used for load calculation, but I still thought that each unit required its own disconnect and branch circuit.
625.40 requires “an individual branch circuit.” To me, that means 1 branch circuit for each piece of equipment.
But, I’ve been wrong before!

 

[tls]

I know that the listed load management feature allows reducing the feeder size and the load used for load calculation, but I still thought that each unit required its own disconnect and branch circuit.
625.40 requires “an individual branch circuit.” To me, that means 1 branch circuit for each piece of equipment.
But, I’ve been wrong before!

In this case, the configuration pictured is specifically laid out in the manual for the (Listed) equipment.

If one of these cables were Al, it would be larger, thus stiffer. Sure, at the same size it's a bit more flexible.

 

[Pioneer74]

Junction boxes are sized based on conduit size.

Conduit size is part of the equation, but junction boxes are based on a box fill calculation. It also takes into account the number of conductors and the method of connecting the wires together. Split bolts, wire nuts etc.

I had five box fill questions on my state Masters test. They can get complicated.

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