Tesla charger w/ adjustable output

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bclumen

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We had a Tesla wall charger install fail inspection. It has adjustable output 12A-80A. We fed with a 50A ckt. and since its mechanicaly adjustable and could be adjusted to draw 100a, the inspector is requiring a 100a cable be installed to it. In your opinion, does 625.40 apply here? Is the max rating the setpoint we set it to or the maximum it could be set to? I'm a bit stumped as only one jurisdiction has required this and we've done similar installs in other counties.

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bclumen said:
We had a Tesla wall charger install fail inspection. It has adjustable output 12A-80A. We fed with a 50A ckt. and since its mechanicaly adjustable and could be adjusted to draw 100a, the inspector is requiring a 100a cable be installed to it. In your opinion, does 625.40 apply here? Is the max rating the setpoint we set it to or the maximum it could be set to? I'm a bit stumped as only one jurisdiction has required this and we've done similar installs in other counties.

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Why would you do that? It's like feeding an electric range top/oven with 20 amps and telling the customer to use the oven or the range top but not both at once. Unless the charger is irreversibly set in some manner to less than 50 amps, there is every reason to suspect it could be used at it's max rating at some point.
 
gadfly56 said:
Unless the charger is irreversibly set in some manner to less than 50 amps, there is every reason to suspect it could be used at it's max rating at some point.
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The maximum advertised current is set via dip switches inside the unit, it is not meant to be user adjustable. While commonly called a charger, the EVSE is just a relay and a little bit of electronics to create a pilot signal to communicate to the EV how much current the car is allowed to draw (and to control the relay). The AC-DC conversion takes place in the car's on-board charger.

Cheers, Wayne
 
gadfly56 said:
Why would you do that? It's like feeding an electric range top/oven with 20 amps and telling the customer to use the oven or the range top but not both at once. Unless the charger is irreversibly set in some manner to less than 50 amps, there is every reason to suspect it could be used at it's max rating at some point.
Click to expand...

bclumen said:
We had a Tesla wall charger install fail inspection. It has adjustable output 12A-80A. We fed with a 50A ckt. and since its mechanicaly adjustable and could be adjusted to draw 100a, the inspector is requiring a 100a cable be installed to it. In your opinion, does 625.40 apply here? Is the max rating the setpoint we set it to or the maximum it could be set to? I'm a bit stumped as only one jurisdiction has required this and we've done similar installs in other counties.

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why couldn't you do this. Hot tubs are done this way all the time. It's all about the jumper settings.
I have seen dual voltage spas 20 to 40 amps. 240v spas 30 -60 amps. Just select the jumper.
This product is UL listed with a select-able output depending on the supply circuit ampacity.
 
bclumen said:
We had a Tesla wall charger install fail inspection. It has adjustable output 12A-80A. We fed with a 50A ckt. and since its mechanicaly adjustable and could be adjusted to draw 100a, the inspector is requiring a 100a cable be installed to it. In your opinion, does 625.40 apply here? Is the max rating the setpoint we set it to or the maximum it could be set to? I'm a bit stumped as only one jurisdiction has required this and we've done similar installs in other counties.

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While it's up to the AHJ I would say that if the settings were protected from user access by a sealed cover or some kind of technician only accessible lock then it should be acceptable. If it's something a user can access with instructions in the owner's manual then I would side with your inspector. Who would not want to charge their car faster if giving the chance to monkey around with the settings because they read something about it on the internet?
 
Funny thing. I replied to this very same question posed by a person at another forum. My answer was to post a YouTube video of Arthur Brown performing his big hit "Fire" .......................
 
wwhitney said:
The maximum advertised current is set via dip switches inside the unit, it is not meant to be user adjustable. While commonly called a charger, the EVSE is just a relay and a little bit of electronics to create a pilot signal to communicate to the EV how much current the car is allowed to draw (and to control the relay). The AC-DC conversion takes place in the car's on-board charger.

Cheers, Wayne
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I agree and see no requirement to size the circuit for the max. After all, that is why the manufacturer made it field settable so it can be tailored to the available supply. One SKU, many applications. Makes sense to me. Also can be reset if and when a larger circuit becomes available. As another poster mentioned, just like many packaged spas and a number of other types of equipment.
 
Also, what if the owner buys a new car in 4 years and can use a higher charge rate? Better to have everything in place now I would think.
 
pv_n00b said:
Also, what if the owner buys a new car in 4 years and can use a higher charge rate? Better to have everything in place now I would think.
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He'd have to buy a new Tesla in 4 years since this does not appear to be a universal charger. Anyone want to offer any action as to the likelihood of Tesla being around in 4 years? Not as a division of someone else.
 
gadfly56 said:
He'd have to buy a new Tesla in 4 years since this does not appear to be a universal charger.
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The protocol is the normal J1772, Tesla just used a proprietary plug. So a Tesla AC charger can be used on other cars with a mechanical adapter. Or if you want to permanently change the EVSE, you can swap out the EV cord and plug set.

Cheers, Wayne
 
wwhitney said:
The protocol is the normal J1772, Tesla just used a proprietary plug. So a Tesla AC charger can be used on other cars with a mechanical adapter. Or if you want to permanently change the EVSE, you can swap out the EV cord and plug set.

Cheers, Wayne
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That's interesting to know.
 
There could be a good reason for limiting the circuit to 50A. Besides cost. For example, if an 80A draw would produce too much calculated load for a feeder or service upstream. Also if the user tries to use too much, the breaker will trip. Unless someone can show me the code section my opinion is that the AHJ is off base.
 
texie said:
As another poster mentioned, just like many packaged spas and a number of other types of equipment.
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jaggedben said:
There could be a good reason for limiting the circuit to 50A. Besides cost. For example, if an 80A draw would produce too much calculated load for a feeder or service upstream. Also if the user tries to use too much, the breaker will trip. Unless someone can show me the code section my opinion is that the AHJ is off base.
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Thank you folks!

Seems like sometimes we go off on the simplest of things.
 
We'd still like to know the model #. Can't find it on Google search. Would like to see the specs.
 
If you look at the manual on page 6 it states the following :

Optional Circuit Ratings
Use a single-phase circuit breaker rated for
100A per phase to obtain the fastest charging.
In certain installation locations, this level of
power isn’t readily available. Therefore, you
can adjust the circuit breaker rating on the
Wall Connector from 15A to 100A (refer to Set
the Operating Current on page 20).

Note: Tesla vehicles must be configured with
optional onboard charging equipment to
accept higher amperages. Contact Tesla if you
have questions about the onboard charging
capabilities of your vehicle.
Click to expand...

Page 18 states the following :

Connect the Wiring
Note: Consult with your local electrician or
refer to your local code for proper wire sizing
appropriate for the currents in your Wall
Connector.

Note: It is the installer's responsibility to
identify whether additional grounding is
required to ensure that local regulations are
met. Grounding must be installed at the power
source and not at the cable entry to the Wall
Connector.
Click to expand...

Then on page 21 it shows this table :

Rotary ---- Maximum -----Circuit
Switch -----Output -------Breaker
Position ----Current
=======================
0 ----------Test mode ----N/A
1 ----------12A -----------15A
2 ----------16A -----------20A
3 ----------20A -----------25A
4 ----------24A -----------30A
5 ----------28A -----------35A
6 ----------32A -----------40A
7 ----------36A -----------45A
8 ----------40A -----------50A
9 ----------48A -----------60A
A ----------56A -----------70A
B ----------64A -----------80A
C ----------72A -----------90A
D----------80A ----------100A
E-----Not a valid selection---N/A
F-----Slave mode-----------N/A
Click to expand...


Off hand I would say the EI was correct in failing this installation. The EI doesn't know if the HO has a Tesla configured for the use of the 80A feature. IMHO, if you're allowing the HO to make the decision as to how much amperage he wants going to his charger then it's up to us to make sure there's ample protection for the wire.
 
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