Tesla charger w/ adjustable output

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goldstar said:
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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Are the conductors protected by the 50 amp circuit breaker?
 
goldstar said:
If you look at the manual on page 6 it states the following :



Page 18 states the following :



Then on page 21 it shows this table :




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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No. The setting switch limits the draw of current, but the car will only draw what it is designed for. The switch is not configuring the car, rather it is telling the car the max it is allowed to draw. That same manual indicates that you can install multiple chargers on 1 branch circuit with the optional accessary and limit the outputs so the branch is not overloaded. What would the inspector say about 4 of these connected to 1 100 amp circuit that the manual clearly states you can do? Also consider this, why would they even have the switch if this was not it's intended use. The manual even states it is for this purpose.
There is a lot of equipment out there these days designed like this such as the previously mentioned packaged spa.
 
infinity said:
Are the conductors protected by the 50 amp circuit breaker?
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Yes, and I understand your point on this. However, this unit can forever only be protected with that 50 amp breaker. If the HO decided to have Tesla fit his car with the capability of the 80 amp charger version he will not be able to use this unit at that level and will continue to tax the breaker. In all likelihood it will trip.
 
texie said:
No. The setting switch limits the draw of current, but the car will only draw what it is designed for. The switch is not configuring the car, rather it is telling the car the max it is allowed to draw. That same manual indicates that you can install multiple chargers on 1 branch circuit with the optional accessary and limit the outputs so the branch is not overloaded. What would the inspector say about 4 of these connected to 1 100 amp circuit that the manual clearly states you can do? Also consider this, why would they even have the switch if this was not it's intended use. The manual even states it is for this purpose.
There is a lot of equipment out there these days designed like this such as the previously mentioned packaged spa.
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Good information to know. Maybe the NEC CMP's need to address this. If we're questioning it I'm sure others are as well.
 
goldstar said:
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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In for a penny, in for a pound. Your logic applies to a 15 A 120 V General Lighting Branch Circuit in a HO occupied Dwelling. . .
 
goldstar said:
If the HO decided to have Tesla fit his car with the capability of the 80 amp charger version he will not be able to use this unit at that level and will continue to tax the breaker. In all likelihood it will trip.
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That doesn't make any sense. If the unit is configured for a 50A circuit, then the EVSE will tell the car to draw at most 40 amps, and whether the car has a 40 amp charger or an 80 amp charger, the circuit will see only 40A continuous.

Now the owner could open up the EVSE, turn the dial to the 80A/100A setting, and then the dual charger car will draw 80A. I expect that should trip a 50A breaker in short order.

Cheers, Wayne
 
wwhitney said:
That doesn't make any sense. If the unit is configured for a 50A circuit, then the EVSE will tell the car to draw at most 40 amps, and whether the car has a 40 amp charger or an 80 amp charger, the circuit will see only 40A continuous.

Now the owner could open up the EVSE, turn the dial to the 80A/100A setting, and then the dual charger car will draw 80A. I expect that should trip a 50A breaker in short order.

Cheers, Wayne
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So assuming that this is how the system works what is the correct answer according the NEC? Does the circuit need to be sized to the largest setting on the unit because someone could simply turn the dial up to 80 amps or do we let the 50 amp breaker protect the conductors even if someone did crank it all of the way up?
 
Here is the curious thing about Tesla wall chargers. I have opened a couple of dozen up and know the following as fact. They come with two 200 amp slow blow fuses installed in them. 200 amp. I have serviced a number of load centers with melted 2 pole 100 amp branch feeder breakers serving Tesla wall chargers that I did not install, so therefore am not able to determine if a loose connection was to fault, or are the breakers badly manufactured and not able to withstand the rated current for them of 80 amps max for periods exceeding 3 hours continuous, or whatever. And note - they were different brands involved, including one from that special German orientated company that starts with an S that has always proclaimed thru out the trades that its breakers are vastly superior to the rest of the crowd. I'm not a manufacturing electrical engineer, but I question the fact that the wall charger unit fuses are 200 amp. And also several times I have had to replace blown ones with the exact same fuse purchased thru Grainger. It doesn't seem like a perfect design to me..........
 
texie said:
No. The setting switch limits the draw of current, but the car will only draw what it is designed for. The switch is not configuring the car, rather it is telling the car the max it is allowed to draw. That same manual indicates that you can install multiple chargers on 1 branch circuit with the optional accessary and limit the outputs so the branch is not overloaded. What would the inspector say about 4 of these connected to 1 100 amp circuit that the manual clearly states you can do? Also consider this, why would they even have the switch if this was not it's intended use. The manual even states it is for this purpose.
There is a lot of equipment out there these days designed like this such as the previously mentioned packaged spa.
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Yep and they are Listed as such. Why should this be a issue.

goldstar said:
Yes, and I understand your point on this. However, this unit can forever only be protected with that 50 amp breaker. If the HO decided to have Tesla fit his car with the capability of the 80 amp charger version he will not be able to use this unit at that level and will continue to tax the breaker. In all likelihood it will trip.
Click to expand...

Yep and the HO could install a larger breaker.
We can't and should not regulate morality.

goldstar said:
Good information to know. Maybe the NEC CMP's need to address this. If we're questioning it I'm sure others are as well.
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No they should not.

:happysad:
Why all the fuss over this. For 30 years there have been package spas with jumpers. We never cared that a user could set the jumper to a higher amperage. The user would be inclined to do this because they were dissatisfied that the heater would not operate while blower and pumps at the same time.

Though we say nothing as we should.

So we have a tesla wall connector and now it's time to get the CMP . HELLO!

infinity said:
So assuming that this is how the system works what is the correct answer according the NEC? Does the circuit need to be sized to the largest setting on the unit because someone could simply turn the dial up to 80 amps or do we let the 50 amp breaker protect the conductors even if someone did crank it all of the way up?
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Still waiting for anyone to cite a code section to back up the inspector's position. 'Someone could modify the installation' is not an NEC backed principle for issuing a correction.
 
jaggedben said:
Still waiting for anyone to cite a code section to back up the inspector's position. 'Someone could modify the installation' is not an NEC backed principle for issuing a correction.
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Exactly

There isn't nothing, the inspector needs to find some other thing to complain about.
 
Sierrasparky said:
Exactly

There isn't nothing, the inspector needs to find some other thing to complain about.
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I agree, this inspector is misinformed. I would not accept his decision. If it did not meet NRTL and NEC requirements, what would be the point of even having the switch? The whole point of the switch setting is to have 1 SKU to cover whatever power is available. Another reason to make these adjustable is that some times the limiting factor is not the inability to install a 100 amp branch circuit but rather may be the service size, or maybe the owner is billed on demand and wants to limit demand. The documentation makes it clear that the unit is designed to be set for the power available.
 
Is the maximum load of the equipment the highest level that the dial within the charger can be set?

2017 NEC:
Part III. Installation
625.40 Electric Vehicle Branch Circuit. Each outlet installed
for the purpose of charging electric vehicles shall be supplied
by an individual branch circuit. Each circuit shall have no other
outlets.
625.41 Overcurrent Protection. Overcurrent protection for
feeders and branch circuits supplying equipment shall be sized
for continuous duty and shall have a rating of not less than
125 percent of the maximum load of the equipment. Where
noncontinuous loads are supplied from the same feeder, the
overcurrent device shall have a rating of not less than the sum
of the noncontinuous loads plus 125 percent of the continuous
loads.
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Ok finally we at least have some code language to debate the meaning of. :roll:

I think it is ambiguous and if the charger limit is set internally in an non-user accessible location I would not dispute that being the maximum load of the equipment. As has been noted above, these things are more or less designed so you can plug in any car and it will only draw what the charger will allow. Someone would have to knowingly mess with the installation to create a danger, it's not possible for the end user to plug in the wrong car or something. And to create a real danger someone would have to change the breaker, which is impossible to idiot-proof on just about any circuit covered by the NEC.
 
The design, user selectable output based on what's current level is available, and the NEC requirement seem to be out of sync.
 
infinity said:
The design, user selectable output based on what's current level is available, and the NEC requirement seem to be out of sync.
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I see no design issue or other. The tesla device is a connector the load is the car. The tesla wall connector is just a smart device telling the car the maximum load.


I am sure that is why is called a connector not a charger. The Tesla guys are smart and do know the codes, I spoke with a charge tech some time ago and he knew all the codes that apply. He knows these products are approved for use as per current code.

We can't fix stupid. People will always not follow the rules. This multi selectable load thing is available to packaged spas, heaters , compressors and many other devices.

people have to follow directions. If the setting is too high then the breaker will trip. If the breaker is replaced with a higher one then. Then process of natural selection will take effect.
Heck the person that owns a Tesla can afford what ever the cost is to upgrade service or feeders , and if they don't and do a shortcut because they think they know better then as I wrote.

Natural Selection.
The code book is already too thick. What we don't need is another.
 
Sierrasparky said:
I see no design issue or other. The tesla device is a connector the load is the car. The tesla wall connector is just a smart device telling the car the maximum load.


I am sure that is why is called a connector not a charger. The Tesla guys are smart and do know the codes, I spoke with a charge tech some time ago and he knew all the codes that apply. He knows these products are approved for use as per current code.

We can't fix stupid. People will always not follow the rules. This multi selectable load thing is available to packaged spas, heaters , compressors and many other devices.

people have to follow directions. If the setting is too high then the breaker will trip. If the breaker is replaced with a higher one then. Then process of natural selection will take effect.
Heck the person that owns a Tesla can afford what ever the cost is to upgrade service or feeders , and if they don't and do a shortcut because they think they know better then as I wrote.

Natural Selection.
The code book is already too thick. What we don't need is another.
Click to expand...


That's all well and good but it still overlooks the actual words of the NEC which are maximum load of the equipment. Are you saying that the 80 amp setting is not the maximum load of the equipment?
 
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