14-50 in a condo complex

[MikeHolliday]

You keep saying this. There is no "16-20". We have been talking about a 6-20.

No, it really isn't. The word "circuit" has its roots from the same source as "circle" for good reason. It is one complete loop. It is one circuit, one loop. You connect the breaker on different places on the panel so that it gets a higher voltage potential, but it is still just one loop of wiring on that circuit, and it uses the amount of current that it says--not double.

Yeah, we already covered all of this by page 2. Load calculation already showed that he only had 10A to spare, so he needs to use the DCC-9 to manage the load.


Yes, I am very well aware of that section of code. And further, that in the newer section 625, which was added in NEC 2017, that it just defines ALL EV charging as continuous loads, regardless.

No, that is not what that means at all. This isn't about "turning it down a little" from how it's installed. That is an internal configuration switch which is set to define the load of the appliance. You don't have to treat the wall connectors as always 100A circuits or 60A circuits because that was what they are built to be capable of. If you are putting it on a 40A circuit and configuring it to BE a 40A circuit device, then that is what you use for the load calculation. It's a 32A continuous, requiring a 40A circuit.


Yeah, all EVSEs are already built to comply with that type of limitation all the time. People just need to make sure they are clear about what they are reading to know what the current number is referring to. The device may be talking about either what current it supplies or what level of circuit it is supposed to be installed on, and obviously those numbers will be different.

Rocky,

By Code you are not allow to lower the setting in the Tesla Wall Connector, just so that you are not over drawing your Breaker Box. The Code State that the Breaker in the Box must have all calculations based on its MAXIMUM output the device possibly draw. Yes, I know know that I can set my Tesla Wall Charger to different Charge Rates, but the Calcultations must be based on its maximum draw which in the case of the Gen 3 Wall Connector is 48 Amps. Since Charging an Electric Car is considered a a Continuous Load the Breakers must be 25% greater than the maximum load, not 20% which is what is normally used. So, in the case of the Tesla Gen 3 Connector, 48 Amps time 1.25 equals = 60 Amps at 240 volts. By IBC (International Building Code) you cannot simply Set the Tesla Wall Connector to a lower setting and use a smaller breaker...

 

[brkaus]

Rocky,

By Code you are not allow to lower the setting in the Tesla Wall Connector, just so that you are not over drawing your Breaker Box. The Code State that the Breaker in the Box must have all calculations based on its MAXIMUM output the device possibly draw. Yes, I know know that I can set my Tesla Wall Charger to different Charge Rates, but the Calcultations must be based on its maximum draw which in the case of the Gen 3 Wall Connector is 48 Amps. Since Charging an Electric Car is considered a a Continuous Load the Breakers must be 25% greater than the maximum load, not 20% which is what is normally used. So, in the case of the Tesla Gen 3 Connector, 48 Amps time 1.25 equals = 60 Amps at 240 volts. By IBC (International Building Code) you cannot simply Set the Tesla Wall Connector to a lower setting and use a smaller breaker...

Yes, you are allowed to lower the WC settings and use that setting for the calculation. The setting is inside the box, locked with security torx and not generally accessed by the end user.

Think about it - the Gen2 WC has a max breaker size of 100a. If your theory was correct, very few houses would be allowed to install one of these. And, they would all need to be wired with 3ga wire.

 

[jstjohnz]

. By IBC (International Building Code) you cannot simply Set the Tesla Wall Connector to a lower setting and use a smaller breaker...

That really makes no sense.

 

[MikeHolliday]

Ok, I will eat a little humble pie, there has been a change this year to the 2020 NEC Code.

This year the NEC (National Electrical Code) has been changed to allow the circuit to be based on the internal setting of an Electrical Wall Connector (Tesla or orther manufactureres.)

The 2020 NEC cleared up this issue; the answer is the circuit is sized to the ‘setting’ selected. So a 100A charger set to 15A would have a 20A circuit supply.

Some modern EV charging equipment is equipped with adjustable load ratings allowing EV chargers to be installed in older homes with small electric services, or other service configurations where limited wiggle room is left for installing additional loads.

In an older home with a 60 Amp or 80 Amp electrical service, installing a 30-or 40-amp EV charging circuit can push the service load calculation over the edge to the point that the service size needs to be upgraded. Some manufacturers solved this dilemma years ago by creating EV chargers that can be adjusted to a lower setting to accommodate limited remaining load capabilities of an electric service.

The problem prior to the code change was not having NEC language that permitted this type of solution. In the 2020 NEC, language was added to allow such installations only for fixed-in-place EV charging equipment with a few conditions that must be followed.

625.42 Rating. The power transfer equipment shall have sufficient rating to supply the load served. Electric vehicle charging loads shall be considered to be continuous loads for the purposes of this article. Service and feeder shall be sized in accordance with the product ratings. Where an automatic load management system is used, the maximum equipment load on a service and feeder shall be the maximum load permitted by the automatic load management system.

Adjustable settings shall be permitted on fixed-in-place equipment only. If adjustments have an impact on the rating label, those changes shall be in accordance with manufacturer’s instructions, and the adjusted rating shall appear with sufficient durability to withstand the environment involved on the rating label. Electric vehicle supply equipment with restricted access to an ampere adjusting means shall be permitted to have ampere ratings that are equal to the adjusted current setting. Sizing the service and feeder to match the adjusting means shall be permitted. Restricted access shall prevent the user from gaining access to the adjusting means. Restricted access shall be accomplished by at least one of the following:

(1) A cover or door that requires the use of a tool to open

(2) Locked doors accessible only to qualified personnel

(3) Password protected commissioning software accessible only to qualified personnel

(The NEC definition of "Qualified Personnel" is “One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved.”)