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2-2-2-4 ALUMINUM SER CABLE for wall connector
- Thread starter gmish
- Start date
Have you looked through the installation manual? I am fairly sure that it recommends copper.
UncleCreepy
Member
In said manual this comes up when you search for "copper":
- Terminal Blocks: 12-4 AWG (3.5 - 25 mm2), copper only
- If installing for maximum power, use minimum 6 AWG, 90° C-rated copper wire for conductors.
- COPPER WIRE TERMINATIONS ONLY for landing in Wall Connector wirebox terminals.
- CAUTION: Use copper conductors only.
The word "aluminum" is nowhere to be found in the manual.
I guess it's safe to say that using copper is more than just a recommendation.
Link
As you can see, 6/3 au se/ser is only good to 50, so…
aluminum wire is used all the time, but no longer for branch circuits. I would be comfortable using it and then bonding over to copper by the WC. plenty of ways to do that.
on the other hand 6/3 cu mc will meet 60 at only 75f, and its roughly $5 a foot. materiak might be a higher, but the labor should be cheaper.
my experience w/contractors suggests whatever inventory they already own and want to turn is instantly their recommendation.
As you can see, 6/3 au se/ser is only good to 50, so…
aluminum wire is used all the time, but no longer for branch circuits. I would be comfortable using it and then bonding over to copper by the WC. plenty of ways to do that.
on the other hand 6/3 cu mc will meet 60 at only 75f, and its roughly $5 a foot. materiak might be a higher, but the labor should be cheaper.
my experience w/contractors suggests whatever inventory they already own and want to turn is instantly their recommendation.
I agree that aluminum or other conductors are not listed in the manual but Tesla is in no obligation to test every conductor out there, code also doesn't mention a copper requirement for EV chargers. Copper is more efficient at transmission than aluminum, thus, higher gauge. I am buying the material and copper 4/2 or 4/3 is super expensive and considering I need 100ft, its costing me anywhere from 300-700 in price difference which is very significant. So thats my rationale of thinking about aluminum. Are there any safety risks?
From what I read, a 6/3 copper is worse than 4/2 aluminum for 60amp just because it fails the 80% guideline and I am concerned about fire risk. A lot of people go with that and apparently its code compliant since there are no 55amp breakers but I don't want to take that chance. For me 6/3 copper and 4/2 aluminum is very similar in price.
ucmndd
Well-Known Member
No, but code does say devices have to be installed per manufacturer’s instructions. The termination points in the wall connector are not meant to be used with aluminum. Don’t do it. Also, the max conductor size for the gen 3 wall connector termination points is 4awg. 2awg aluminum will not fit.
If you insist on using aluminum for most of the run, transition to copper for the last few feet. There are various safe ways to do so.
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ucmndd
Well-Known Member
You can’t treat all 6awg copper the same. As pointed out above 6/3 MC can be used at the 75C rating and is perfectly acceptable for a 60 amp circuit.
6/3 NM-B is not because NM cable must use the 60C rating.
A common misconception. Lots of people do it but it’s definitely not code complaint. The round up rule doesn’t apply here because the calculated load is greater than the max ampacity rating of the conductors.
FWIW, you don’t need 6/3 cable for a wall connector. You need 6/2. No need to run an extra conductor if you’re sensitive to price.
I am lost and can't find a cheaper <$3-4 / ft for 4/2 or 4/3 copper. I can see 6/2 <$2.8 per ft but as soon as I go to 4/2, prices are twice or more higher. So rather than getting it for $300 with taxes for 100 ft, I am getting 600+. I looked at Amazon / Ebay/ Homedepot. Also, there are so many options like Type W, UFB, NMC etc.
Looking more at it, this seems like a good compromise: 6/2 Stranded Metal Clad MC Copper Conductor 600V Aluminum Armored Cabl (nassaunationalcable.com)
ucmndd
Well-Known Member
No, not trying to do it myself but electrician is quoting a lot for upgrading the wire so I offered to buy the wire myself and then he will do the rest. For now, ll go with 6/2 Stranded Metal Clad MC Copper Conductor 600V Aluminum Armored Cabl (nassaunationalcable.com)
That's not how that works. We're not comparing the numbers that the cash register shows for those two cases. I have two friends who are electricians, and one of them told me about this. He said the electricians generally charge about 25% markup on whatever parts they need to go buy for a job, because they are basically running errands for you having to go there and pick it out and buy it and then bring it to your house.
And to reiterate on this from what @UncleCreepy posted from the user manual. You really can't use aluminum wire directly into the terminals of the wall connector. The wire lugs that the wires have to screw into are just not the right type to allow either wire type. They are for copper only. It takes certain wire lugs made for allowing aluminum, which the wall connector just doesn't have. So if you have a really long wire run, sure, you could run most of the distance with aluminum wire for the cost savings, but then you need to terminate those wires in some other kind of box that is made to take AL wire, and then you can do the last short run with copper, which was what @ucmndd was describing.
Sure, somewhat cheaper, but that's a lot of markup. The guy I know who did my installation straight-up told me it would be cheaper for me to go get the parts myself than what it would be for him to go get it. He gave me a parts list so I could go shop for it.
Most supply houses will happily sell to anyone walking in off the street. It's actually a pretty good life hack to figure out the supply houses for all major trades and other niche product shops in your area. The amount of neat sh|t you can just walk in and buy is amazing and you don't need to give Bezos a cut and wait 2+ days for shipping.
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