Dialed in ev chargers

Status
Not open for further replies.
A

AV ELECTRIC

Senior Member
I see ev chargers like Ford that can require up to 80 amps but can be dialed down on a type of internal dip switch on the circuit board for lowered amperage charging rates . I have read that for this 80 amp charger you can dial down to a lower ampacity and the circuit supply can be rated for that dialed down ampacity . To me that makes no sense as what stops one from dialing it back up to a maximum charge of 80 amps . I thought a devices overload protection is based on it's maximum ampacity . I also see this plugging into a 120 volt circuit . You can dial it in for a 15 amp circuit or 20 and the charger doesn't differentiate from either .
 
The NEC specifically allows this as long as the deprecated value either requires a tool to access the hardware switch or it is a software setting that is password protected from casual users.

It no more of a risk than a homeowner swapping out a breaker for a larger size.
 
I just find it odd that a device rated at a maximum rating can be altered to a lower rating and that rating can be what is used for over currant protection . I get a Homeowner can do what they want like change a breaker which has risk . I just witness a video of an electrician putting in electrical for ford's EV charger . The owner thought he got a 80 amp setup but it looked more like a 40 amp setup . He dialed it up to 80 amps but good for him the unit went into fault mode and stopped charging . He had the electrician come back and install a 100 amp circuit . It just seems to me the code blew this one with the electrical fires we have seen from charging EVs . It was disturbing to see this guy pull off the plastic cover and turning the dial to different amperages with a small screw driver not having a clue what he was doing . I think it's a problem .
 
We’ll have to see how this all plays out. Tesla Wall Connectors have worked this way for 10 years and as far as I’m aware, there haven’t been widespread issues. There are alway going to be idiots doing stupid things. Question is how many?

You mention fires from EV charging. I really haven’t seen any reported, not that I’ve actively searched.

Most EV-related fires are due to defective battery issues, namely Chevy Bolts.
 
retirede said:
We’ll have to see how this all plays out. Tesla Wall Connectors have worked this way for 10 years and as far as I’m aware, there haven’t been widespread issues. There are alway going to be idiots doing stupid things. Question is how many?

You mention fires from EV charging. I really haven’t seen any reported, not that I’ve actively searched.

Most EV-related fires are due to defective battery issues, namely Chevy Bolts.
Click to expand...
Yeah that may climb as more electric vehicles enter the home . I wonder how much protection the chargers and the vehicles can have . Arc fault breakers have been installed for some years now and they do a good job at some of the big reasons for fire . For chargers they provide GFCI protection . Why not include arc fault which to me with battery charging would be more of a priority . The industry will adapt as with the NEC as this becomes more of the norm. Probably allot of work for electricians . Mostly good but some not so good situations that shotty work and failed equipment would have . I would be a bit concerned having a electric vehicle being charged in my garage while I sleep .
 
Even if you set your EV for the circuit's rating, another user without a dialed-back charging setting could plug in.
 
AV ELECTRIC said:
Yeah that may climb as more electric vehicles enter the home . I wonder how much protection the chargers and the vehicles can have . Arc fault breakers have been installed for some years now and they do a good job at some of the big reasons for fire . For chargers they provide GFCI protection . Why not include arc fault which to me with battery charging would be more of a priority . The industry will adapt as with the NEC as this becomes more of the norm. Probably allot of work for electricians . Mostly good but some not so good situations that shotty work and failed equipment would have . I would be a bit concerned having a electric vehicle being charged in my garage while I sleep .
Click to expand...

I would disagree that arc fault detection provides useful protection. The biggest risk is from overheating at connection points. By the time there’s an arc, it’s too late.

All EVs have thermal monitoring in the J1772 / CCS socket just for this reason. And most (but certainly not all) plug in EVSEs have thermal monitoring both internally and in the AC plug.

Full disclosure: I drive an EV that charges in my garage. I’ve done my homework and don’t feel it’s any less safe than the car with a tank of gasoline parked next to it.

https://www.usatoday.com/story/money/cars/2022/07/09/ford-recall-suv-owners/10015493002/
 
AV ELECTRIC said:
they do a good job
Click to expand...
They do? I don't think we have enough data yet to say one way or the other.

Since different states adopted the NEC's AFCI provisions in different years, a study is certainly possible. Look at homes built in certain years, where in some states those have AFCIs and other states they don't, and look at the rate of fires in each case. But the overall rate might be so low that I expect there won't be a signal yet, if there ever will be.

Cheers, Wayne
 
wwhitney said:
They do? I don't think we have enough data yet to say one way or the other.

Since different states adopted the NEC's AFCI provisions in different years, a study is certainly possible. Look at homes built in certain years, where in some states those have AFCIs and other states they don't, and look at the rate of fires in each case. But the overall rate might be so low that I expect there won't be a signal yet, if there ever will be.

Cheers, Wayne
Click to expand...
I have seen arc faults in action even with a slightly loose connection and they have tripped . I have only changed a couple out that went defective on the Siemens side . I installed them on my daughter's aluminum wiring and it gets me to sleep at night or at least better
 
retirede said:
I would disagree that arc fault detection provides useful protection. The biggest risk is from overheating at connection points. By the time there’s an arc, it’s too late.

All EVs have thermal monitoring in the J1772 / CCS socket just for this reason. And most (but certainly not all) plug in EVSEs have thermal monitoring both internally and in the AC plug.

Full disclosure: I drive an EV that charges in my garage. I’ve done my homework and don’t feel it’s any less safe than the car with a tank of gasoline parked next to it.

https://www.usatoday.com/story/money/cars/2022/07/09/ford-recall-suv-owners/10015493002/
Click to expand...
Yeah it comes down to how comfortable you are . I presume if there is a problem you can be notified by maybe your phone . Yes if there is some thermal detection that can disconnect the charging system that's a bonus . I don't think they have built these systems yet to be idiot proof so I presume there will be problems . Most electrical problems don't lead to fires . They cook and disconnect themselves for the most part . Maybe short circuit
 
I did another post on this topic that has to do with calculating the correct wire to use to direct wire a residential charger. The charger's terminals are rated 105* C and can accommodate #6 awg copper. Due to the complexity of the house, conduit cannot be used, so first choice was 6/2 Romex with a 50A breaker. This allows for 40A charger load. The owner wants that extra 7 miles per hour of charge and requested increasing the circuit size so the load of the charger is 50A requiring a #4 which does not fit the charger's terminals, and a 60A breaker. There is no 4/2 Romex so 4/3 would be used. A significant cost increase. A work around is to splice #6 to the #4 so it can connect to the charger. I don't agree with this since the short pieces of #6 could see 60A. Since MC cable with #6 awg has no restriction to the 60*C column in 310-15(B) (16) as Romex does, the 75* C ampacity of 65A can be used. A 60A breaker would have 75*C, the Charger terminals 105*C.
Then again, once it is installed, the owner can dial it up to 70A or 80A if he chooses.
 
Amps said:
I did another post on this topic that has to do with calculating the correct wire to use to direct wire a residential charger. The charger's terminals are rated 105* C and can accommodate #6 awg copper. Due to the complexity of the house, conduit cannot be used, so first choice was 6/2 Romex with a 50A breaker. This allows for 40A charger load. The owner wants that extra 7 miles per hour of charge and requested increasing the circuit size so the load of the charger is 50A requiring a #4 which does not fit the charger's terminals, and a 60A breaker. There is no 4/2 Romex so 4/3 would be used. A significant cost increase. A work around is to splice #6 to the #4 so it can connect to the charger. I don't agree with this since the short pieces of #6 could see 60A. Since MC cable with #6 awg has no restriction to the 60*C column in 310-15(B) (16) as Romex does, the 75* C ampacity of 65A can be used. A 60A breaker would have 75*C, the Charger terminals 105*C.
Then again, once it is installed, the owner can dial it up to 70A or 80A if he chooses.
Click to expand...

You could splice the #4 Romex with #6 THHN, and you’re good to go. If there isn’t sufficient space in the EVSE, you’d need a junction box for the splice.
 
wwhitney said:
They do? I don't think we have enough data yet to say one way or the other.

Since different states adopted the NEC's AFCI provisions in different years, a study is certainly possible. Look at homes built in certain years, where in some states those have AFCIs and other states they don't, and look at the rate of fires in each case. But the overall rate might be so low that I expect there won't be a signal yet, if there ever will be.

Cheers, Wayne
Click to expand...
We are just starting to get near enough time since first AFCI's were required, and those were only in bedrooms and some places were amending those requirements out of the code in early years as well. Here we amended them out until adoption of 2008 NEC, and it was late 2008 or early 2009 when we finally adopted it.

I think the real test will be when components being "protected" are getting to be 20-25 years old. Then the next question becomes does the AFCI still work like it did when it was new?

On top of that I still think many more fires are started by "glowing connections" than by arcing, yet an AFCI can not detect a glowing connection as it is basically a resistive load to the AFCI. 120 volts just can not sustain an arc without intervention of something feeding more material into the arc. If you ever used an arc welder this is easy to understand, you need to feed more material into the arc to keep it going if gap grows too large arc goes out.
 
retirede said:
The NEC specifically allows this as long as the deprecated value either requires a tool to access the hardware switch or it is a software setting that is password protected from casual users.

It no more of a risk than a homeowner swapping out a breaker for a larger size.
Click to expand...
Do you have a code reference? Also I agree with you that someone can alter the installation in the future but IMO flipping some DIP switches is not the same as removing and replacing a circuit breaker.
 
retirede said:
You could splice the #4 Romex with #6 THHN, and you’re good to go. If there isn’t sufficient space in the EVSE, you’d need a junction box for the splice.
Click to expand...
#4 romex out of the wall into the back of a 4-11/16 sq box. Then 3/4 " EMT from the box to the charger. I can use the 75*C or even 90*C rating for the #6 ? So then a 60A breaker is not over amping the #6? Does this make sense?
 
Status
Not open for further replies.
Top