Calculating OCPD

retirede

Senior Member
Location
Illinois
Yes!
You are right.
There are two popular models on the market. The regular small charger that you can plug into a regular 120 volt outlet --but will take the whole night --around eight to twelve hours to achieve a full charge from an almost depleted EV.

The fast charging model will take around four hours for a full charge. The OCPD required for this model is 40 Amps. The load (nameplate) is rated 32 Amps.
So, considering continuous load 32 x 1.25 = 40.

There is no higher rated yet on the market.. . .not even the Tesla X Sports Model as far as I know.

Most chargers are adjustable e.g. from low charge to high charge.. . . usually in three increments
I am installing one right now. . . and its a high charge model that requires a 40 A OCPD.
All high charge models require a minimum 40 Amps, 2 Pole 240 volts.

As you stated a smaller OCPD can be installed with appropriately sized conductors.

I am doing this for a friend Pro Bono.
This is the second one I’m installing for another friend.
The downside for being a sparky. :) Can’t say no. :(
1) Depending on the size of the vehicle battery, a 120V EVSE will likely take closer to 3 days to fully charge.

2) EVSEs that deliver 48A on a 60A circuit are not uncommon. I have one. About 8 hours to fully charge.

“Fully charge” meaning from nearly depleted to 100%. In real life, the typical evening charge is more likely to start at 10% or more and stop at 80-90%.

YMMV
 

myspark

Senior Member
Location
SCV Ca, USA
Occupation
Retired EE
1) Depending on the size of the vehicle battery, a 120V EVSE will likely take closer to 3 days to fully charge.
2) EVSEs that deliver 48A on a 60A circuit are not uncommon. I have one. About 8 hours to fully charge.
“Fully charge” meaning from nearly depleted to 100%. In real life, the typical evening charge is more likely to start at 10% or more and stop at 80-90%.
YMMV
It’s hard to make a final say on what is the standard in terms of charging plug that will fit in your EV.
Electric charging systems is still an evolving technology that standards in Europe may not apply in North America --for example.
Japan and China are coming up--and some are already on the market- that can interface with Solar and the Grid System.
Although it is fair to say that most of the Charging systems that we see in North America have
interchangeability.

The first one I installed was for the Tesla Type 3. This new one I’m working on is for Chevy Bolt.
The Tesla Model is non-adjustable type that is fixed output vs the CHEVY BOLT . There maybe other models that may differ from this one model though.

For more info check this website :
 

retirede

Senior Member
Location
Illinois
It’s hard to make a final say on what is the standard in terms of charging plug that will fit in your EV.
Electric charging systems is still an evolving technology that standards in Europe may not apply in North America --for example.
Japan and China are coming up--and some are already on the market- that can interface with Solar and the Grid System.
Although it is fair to say that most of the Charging systems that we see in North America have
interchangeability.

The first one I installed was for the Tesla Type 3. This new one I’m working on is for Chevy Bolt.
The Tesla Model is non-adjustable type that is fixed output vs the CHEVY BOLT . There maybe other models that may differ from this one model though.

For more info check this website :
Every single EV sold in the US other than Tesla has a standard J1772 connector. There can be incompatibilities between EVSEs and the onboard chargers, but not because of the charging plug.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector
Funny how EV owners expect everything for nothing...

-Hal
or on the taxpayer's dime :)
TDEC and TVA signed an agreement to collaborate and fund a network of fast charging stations every 50 miles along Tennessee’s interstates and major highways
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
I am reviewing plans for a residential car charging station. 240v and the charger has the ability to charge at multiple output ratings from 16 amps up to 60 amps, the amperage can either be set within the charger or it can be changed with an app on your phone. .
What is the make and model? The only reasonable way for an EVSE to be so implemented is for an internal setting on the EVSE to provide an upper limit on charge rate, and then for the app to only allow setting the rate lower than that, not higher than that. In which case it makes sense to size the OCPD and wiring based on the actual internal EVSE current setting, not the maximum possible value of that setting (50A per later discussion).

Cheers, Wayne
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
What is the make and model? The only reasonable way for an EVSE to be so implemented is for an internal setting on the EVSE to provide an upper limit on charge rate, and then for the app to only allow setting the rate lower than that, not higher than that. In which case it makes sense to size the OCPD and wiring based on the actual internal EVSE current setting, not the maximum possible value of that setting (50A per later discussion).

Cheers, Wayne
The code does not make this distinction though. This is another case where someone is trying to prevent some future bad thing. The code just does not require it.
 

retirede

Senior Member
Location
Illinois
or on the taxpayer's dime :)
TDEC and TVA signed an agreement to collaborate and fund a network of fast charging stations every 50 miles along Tennessee’s interstates and major highways
The government is paying for 15% of the project. The money is from the Volkswagen diesel emissions settlement, not tax dollars.
 
Top