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Wire Guage clarification help.

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dradam

dradam

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Just need to review the allowable conduit fill charts based upon the type of conduit you plan to use so there is sufficient air space around the wires for cooling. The wiring charts are either based on the wires in free air which allow them to get a bit warmer and be naturally cooled and carry more current or wires encased in conduit or enclosure that takes into account that conduit is going to get warm as the wires naturally warm carrying current and not allow the wires to cool as much as if they were on a pole in the air.
So the conduit fill charts are as important as the wire sizes them selves

hope that helps
Super helpful! I plan to use 1" flex pvc for 3x 6awg and a ground Likely 8 AWG. One will be an unused neutral which will not be live unless needed in the future. This should far exceed minimum requirements.

Thank you again.
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Good luck with your project and always be safe

Work everything de-energized

And always test before touching any components to verify above
 
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dradam

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Good luck with your project and always be safe

Work everything de-energized

And always test before touching any components to verify above
Thank you , I will be helping my electrician but will be super careful. I appreciate your responses and concerns.
 

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You can't run 6 AWG Romex (NM-B in the chart below) which is rated for 55amps off a 60amp breaker, as the breaker can't have a higher trip rating than the circuit wire max capacity for obvious reasons (think of a short circuit which would allow 60amps to run through the 55amp rated wire).

4 AWG Romex would probably be easier to run then installing conduit and pulling 3 or 4 THHN cables through it depending on how many twists and turns it makes.

It's a little concerning that the electrician was willing to install a 60 amp breaker on 55amp rated cable because "it will not exceed 48 amp load".. well accidents happen and that's why we use breakers in the first place. Secondly, a 55 amp rated 6 AWG Romex cable needs to be derated by 20% under "continuous load" (which is how our EVSE's are classified) so that would be 44 amps max load, not 48 amps on that 6 AWG Romex.

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Mine unfortunately ran 6-3 Romex to a 60 AMP breaker. I set my scheduling at home to charge at 42 just to be under that 44 upper number. He swears I'm fine at 48 but I'm not going to risk it when I don't need the speed. The Rivian charger is set for 48 as well but should I just change the dip switches to 40 on the charger to eliminate all the workarounds? No one else would ever use my charger but me and it's my first day with it so just trying to weigh out my options.
 

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Mine unfortunately ran 6-3 Romex to a 60 AMP breaker. I set my scheduling at home to charge at 42 just to be under that 44 upper number. He swears I'm fine at 48 but I'm not going to risk it when I don't need the speed. The Rivian charger is set for 48 as well but should I just change the dip switches to 40 on the charger to eliminate all the workarounds? No one else would ever use my charger but me and it's my first day with it so just trying to weigh out my options.
I would set it to 40 and be done with it. That way you will not run into a situation where you forget to set it in the truck.
 

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dradam

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I just ran 6awg in flex metal cable. It should be ok at 48 A. It is rated at 65 A at 75 c . Despite that as an added precaution I may set my charger dip switches to 40 A. As many have pointed out here if it take 5 hours to charge or 3 it makes no difference to me between midnight and 6Am, and May be better for the batteries.
 

runwithscissors

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I just ran 6awg in flex metal cable. It should be ok at 48 A. It is rated at 65 A at 75 c . Despite that as an added precaution I may set my charger dip switches to 40 A. As many have pointed out here if it take 5 hours to charge or 3 it makes no difference to me between midnight and 6Am, and May be better for the batteries.
I agree for me it's no difference but when I just upgraded to 200A service to be handcuffed like this is annoying. I could've just kept my old 100A service and used something like 40A breakers and charged at 32A or even 24A.

The best part of the day is they all leave and my charger isn't working so I'm like I bet they didn't connect the front plate to the charger with the cable so I had to run to Home Deport for a T20 security bit and voila that was the issue. I don't even know if the Rivian charger comes with the bit in the box but they never left it behind if it was included. I made sure to shutoff the breakers beforehand so I will probably do it again for the 40A dip switch change and just put it behind me.
 

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I don't even know if the Rivian charger comes with the bit in the box but they never left it behind if it was included.
It does come with the bit in the box. It's in a plastic baggie at the bottom. Placed just where you'll find it after you've already completed the job using something else, LOL. ?

IMHO should be taped to the top.
 

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Any thoughts on 6 awg Romex to a 60amp breaker if the run is only like 5 feet? Shorter wire should mean less resistance and lower temperatures. Wires are also in an uninsulated wall cavity. Don’t really want to get another electrician back out to redo the job.
 

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Romex is technically not code on a 60a breaker running 48a circuit. However, many inspectors will allow it, and the local inspector is the one who has final decision on the install. This is extremely common in CA and other EV dense areas, which is why so many electricians push Romex. It's also significantly easier to work with and cheaper.

Remember, the wires inside Romex are acceptable for the circuit, but the Romex jacket is not rated for the temps of a 48a circuit. If you are installing in interior, loosely climate controlled areas (IE, not an attic), you will almost assuredly, never have a problem. There would be enough heat dissipation.
 
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dradam

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6awg romex is not to code. I used 6-3 awg xhhw-2 that came in 3/4 flexible metal conduit. Was about $3.50/ foot. 65 amps at 75 deg C. Has better thermal ratings and flexibility than thhn. fittings are common at the big box stores.
 

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6awg romex is not to code. I used 6-3 awg xhhw-2 that came in 3/4 flexible metal conduit. Was about $3.50/ foot. 65 amps at 75 deg C. Has better thermal ratings and flexibility than thhn. fittings are common at the big box stores.
Something like THIS??

imagine I could just drill a hole straight through my wall out the back of the garage and run the 3ft along the exterior into the subpanel? No need to extra conduit etc?
 
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dradam

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That image looks like what I used, but my run was all indoors. I don’t know if it is code for outdoor use.
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