Universal Wall Connector Install

[MizterLock]

Hi All,

I just bought a Universal Wall Charger and am working with a friend who is a semi-retired electrician to install it. Looking to put a 60amp circuit in to get the maximum charging rate. He's never installed a car charger before, so we're both researching this a bit first. I don't have a Powerwall or Solar system, so it's just a charger for now. He mentioned that we may need to put a disconnect switch in, but wasn't completely sure and still looking into local code requirements. From what I can tell this isn't necessary since you can't do vehicle to grid with Teslas (minus the CT, and I'm not getting CT unfortunately). The documentation for the Wall Connector even says "External disconnect switches are neither required nor recommended". None of the videos I've watched mentioned anything about a disconnect either.

For my sanity can anybody else confirm a disconnect isn't necessary in this scenario?

Much Thanks
MizterLock

 

[Eric33432]

Not required in the US unless your local jurisdiction for some reason needs it.

Tell him an EVSE is a continuous load and the circuit should be derated 20%. For example, if installing 60 amp circuit, which will charge car at 48 amps, you will need #4 NM-B, #6 MC, or #6 THHN/THWN-2 in conduit. Tell him #6 NM-B, when derated, is only good for 44 amps continuous load. If he is an actual licensed electrician, he should understand this. Ask him to ensure your electrical service can stand a 48 amp load that is on for hours, and to do a load study if needed.

 

[MizterLock]

Perfect, I will pass this along.

 

[miimura]

In addition to above, a disconnect is only required for a device rated for more than 60 amps or more than 150V above ground. Split phase 240V household power in North America is only 120V above ground. A Gen3 Wall connector doesn't meet either of those requirements, so the disconnect is not required.

 

[MizterLock]

Noted. Thank you.

 

[Watts_Up]

In addition to above, a disconnect is only required for a device rated for more than 60 amps or more than 150V above ground. Split phase 240V household power in North America is only 120V above ground. A Gen3 Wall connector doesn't meet either of those requirements, so the disconnect is not required.

I try to remember about something that might be an NEC recommendation, that if a main power switch or a circuit breaker
cannot be accessible or visible from a distant device, a disconnect switch should be installed next to this device,
to prevent that if someone might accidentaly turn back the main power switch or circuit breaker,
a technician working on this device might not be aware that the power has been turned back?

 

[Eric33432]

I try to remember about something that might be an NEC recommendation, that if a main power switch or a circuit breaker
cannot be accessible or visible from a distant device, a disconnect switch should be installed next to this device,
to prevent that if someone might accidentaly turn back the main power switch or circuit breaker,
a technician working on this device might not be aware that the power has been turned back?

That is a requirement (not a recommendation) for an air handler (many now have a built in disconnecting means or circuit breaker) or an air conditioner condensing unit, but not for an EVSE of 60 amps or less if the voltage is 150 volts or less to ground (a 240 volt residential circuit has 240 volts across line 1 and line 2, but the voltage to ground from these lines is 120 volts). According to Article 625.43 of the NEC:

Electric vehicle supply equipment rated more than 60 amperes or more than 150 volts to ground, the disconnecting means shall be provided and installed in a readily accessible location. The disconnecting means shall be capable of being locked in the open position. The provision for locking or adding a lock to the disconnecting means shall be installed on or at the switch or circuit breaker used as the disconnecting means and shall remain in place with or without the lock installed. Portable means for adding a lock to the switch or circuit breaker shall not be permitted.

It is also not a requirement for a range, dryer, or any appliance that is connected with a cord and plug to a NEMA receptacle (because when servicing the appliance it can be easily un-plugged) but I have seen simple lockout devices in newer construction on the circuit breakers for hard wired cooktops and other hard wired appliances such as wall ovens, dishwashers, etc, although sometimes the appliances are also cord and plug connected to a receptacle. I suppose this requirement could be applied to an EVSE by an inspector, but I could not find a code reference requiring that.

 

[MizterLock]

Hi again,

So a couple more questions. I'm contemplating between buying a new 3, Y, or S this year. Some articles on the internet suggest Tesla would support bi-directional charging by 2025.

Do we know yet if any of the current models now support this? Doesn't seem like it outside of the CyberTruck.
Would it make sense or hurt anything to put a switch in just in case for future vehicles that do support V2G?

Thanks for any input you can provide.

 

[MizterLock]

Some added context to the above questions, my friend was saying I may need a transfer switch and disconnect switch if it's V2G. He's extra cautious with meeting code and making sure we don't send power back into the grid in a power outage.

 

[Supcom]

Hi again,

So a couple more questions. I'm contemplating between buying a new 3, Y, or S this year. Some articles on the internet suggest Tesla would support bi-directional charging by 2025.

Do we know yet if any of the current models now support this? Doesn't seem like it outside of the CyberTruck.
Would it make sense or hurt anything to put a switch in just in case for future vehicles that do support V2G?

Thanks for any input you can provide.

The only Tesla that can send power out of the charge port is the Cybertruck. As I recall, the other models do not have the hardware required for this.

 

[Eric33432]

Some added context to the above questions, my friend was saying I may need a transfer switch and disconnect switch if it's V2G. He's extra cautious with meeting code and making sure we don't send power back into the grid in a power outage.

If you do vehicle to grid you do not need a transfer switch, but if you do vehicle to house during a power failure you have to have a gateway device, similar to a generator transfer switch to isolate the house from the grid. You also have to have something, similar to an autoformer, to create the neutral connection, as the vehicle, and the wall connector, are strictly 240 volt devices.

When operating vehicle to grid, the transformer serving the residence serves the purpose of an autoformer. But when isolated from the grid, you would need an autoformer, or similar device.

But really, even if you just want to do vehicle to grid, you will need a gateway or similar device to disconnect the house during a power failure, unless the vehicle can sense the fact that the power has failed and turn itself off like a solar inverter will do.

 

[MizterLock]

Appreciate it. We should be good. I've got no plans to do that, should be a standard install. He got me overthinking it a bit as well . My mind was wandering to if Tesla was secretly putting the capability in the new model 3 or other models and just disabled it for a future announcement (since they tend to make improvements/changes quite frequently). But then I'm like they better have protections/sensors in place like your last statement says or there's going to be major issues.

I wonder how that works on the CyberTruck if you don't want to use the Powershare/V2H capability, if there's a sensor on the truck or if everyone would need a gateway device installed with their charger? Separate message board question.

 

[Eric33432]

Appreciate it. We should be good. I've got no plans to do that, should be a standard install. He got me overthinking it a bit as well . My mind was wandering to if Tesla was secretly putting the capability in the new model 3 or other models and just disabled it for a future announcement (since they tend to make improvements/changes quite frequently). But then I'm like they better have protections/sensors in place like your last statement says or there's going to be major issues.

I wonder how that works on the CyberTruck if you don't want to use the Powershare/V2H capability, if there's a sensor on the truck or if everyone would need a gateway device installed with their charger? Separate message board question.

Pretty sure Tesla would not require a gateway as that can be expensive and difficult to install and would severely limit the sales of the CT is you had to install such a device.

CT V2G has been discussed in these forums a lot.