2018 Leaf - Charger throws fault on 240V

[HerdingElectrons]

You realize you quoted a 1-year-old post where the OP hasn't returned since his OP don't you?
I doubt they'll be back

Fully aware & sure that's a possibility. It's also a possibility they will check in here once a quarter or once a year & none of that changes the reality that I'm curious where they live where there's 208V in a residential location.

I will continue to 'worry' about my posting choices & I hope that you can consider doing the same.

 

[GerryAZ]

FWIW, there are a few older neighborhoods in Phoenix with 3-phase, 208-volt service to single-family residences.

I believe JeffGamer's issue is that the No. 10 AWG wire overheats so the connections progressively deteriorate, net impedance of the circuit increases so voltage at the receptacle drops, car draws more current due to lower voltage, and the situation cascades until the car fails to charge. It works after the electrician fixes the connections because the voltage is back up to 240 or so and the current is slightly lower. As I have noted before in previous posts, the Nissan portable dual-voltage EVSE needs at least a 40-ampere circuit (minimum No. 8 AWG wire), but preferably a 50-ampere circuit (minimum No. 6 AWG wire) with NEMA 14-50 receptacle to charge at nominal 240-volts and it will not charge from nominal 208-volt circuits even if voltage is a little higher, say 212 or so.

 

[SageBrush]

As I have noted before in previous posts, the Nissan portable dual-voltage EVSE needs at least a 40-ampere circuit (minimum No. 8 AWG wire), but preferably a 50-ampere circuit (minimum No. 6 AWG wire)

Ampacity tables seem to take the temperature rating into account. Am I reading correctly ?

 

[SageBrush]

As I have noted before in previous posts, the Nissan portable dual-voltage EVSE needs at least a 40-ampere circuit (minimum No. 8 AWG wire), but preferably a 50-ampere circuit (minimum No. 6 AWG wire)

Ampacity tables seem to take the temperature rating into account. Am I reading correctly ?

 

[goldbrick]

I'm sure Wayne can give a better answer but unless there are multiple wires bundled together (eg in conduit) then the ampacity tables take temperature into account.

When you start packing many wires into a single raceway then de-rating comes into play but if it's just a single cable, eg NM-B aka Romex, through a stud wall then there is no de-rating required and the ampacity table value for the type of cable accounts for temperature (eg the conductors in NM-B cable are rated for 90C although the ampacity charts are for 60C).

I think the limiting factor for temperature is usually the terminal ratings.

 

[GerryAZ]

Temperature rating of particular wires in use needs to be considered along with anticipated temperature of installed location(s), ampacity derating charts for temperature, temperature limitations of electrical equipment being connected, and derating factor for more than 3 current-carrying conductors in a conduit, In many cases, receptacles, circuit breakers, disconnect switches, etc. have wire temperature limitations of either 60 C or 75 C so the 90 C wire temperature cannot be considered for the termination locations (but may be considered if part of the conductor run is through a higher ambient temperature area such as an attic in a hot climate). In general, NEC limits overcurrent protection for No. 10 AWG to 30 amperes so a 40-ampere or 50-ampere circuit requires larger wire if NEC applies. Some jurisdictions have other requirements so I did not get too specific.

 

[SageBrush]

Over my head, guys

I look at charts like this

And see different ampacities for the same copper AWG.

 

[GerryAZ]

Different insulation materials have different maximum allowable conductor temperatures (60 C, 75 C, or 90 C). That chart is probably based upon 30 C ambient temperature so there is another table with multipliers for higher (less than 1.0) or lower (greater than 1.0) ambient temperatures. The asterisks for 10, 12, and 14 AWG wire refer to notes that say maximum overcurrent protection is 30 amperes for 10 AWG, 20 amperes for 12 AWG, and 15 amperes for 14 AWG even when the tables and calculations allow higher currents.

 

[goldbrick]

The short answer is just use the values listed in the 60C column. 99.9999% of residential wiring should be covered by that.

 

[lorenfb]

For detailed electrical info;

https://www.amazon.com/Electrical-Black-Book-2nd-USA/dp/1921722509/ref=sr_1_3?crid=1WF24KR8SUDSS&dchild=1&keywords=electrical+black+book+2021&qid=1630525049&sprefix=Electrical+Black+Book%2Caps%2C219&sr=8-3

 

[JeffGamer]

Thanks, TriggerHappy, jjeff and GerryAZ, for the feedback...I really appreciate it! I'm going to forward the comments to the electrician. In your opinions...do you think this is something he should have known all along? He's going to want to charge me another $300 - $400 to redo the wiring, though if he should have known this when he installed the wiring, that really isn't the right thing to do....

 

[Triggerhappy007]

Thanks, TriggerHappy, jjeff and GerryAZ, for the feedback...I really appreciate it! I'm going to forward the comments to the electrician. In your opinions...do you think this is something he should have known all along? He's going to want to charge me another $300 - $400 to redo the wiring, though if he should have known this when he installed the wiring, that really isn't the right thing to do....

I would give him all the facts. How did you ask for the install? Did he look at the specs on the EVSE before installing? Is he self employed or works for someone else? Do you still have the work order?

I have a feeling he used really poor wiring or even 12 gauge. Yikes! I'm not a lawyer so cannot give law advice, but you may have to go that route.

 

[GerryAZ]

If the electrician installed a NEMA 14-50 receptacle (typical for RV or kitchen range), then he/she should have used a minimum of No. 8 AWG wire with 40-ampere breaker or No. 6 AWG wire with 50-ampere breaker to comply with codes in most locations in the USA. If a NEMA 14-30 receptacle (typical for clothes dryer) was installed, then No. 10 AWG with 30-ampere breaker would be normal. Unfortunately, a 30-ampere circuit is not suitable for charging at 240 volts with the Nissan dual-voltage portable EVSE.