60A Breaker -> 4 gage or 6 gage wire?

[SDRick]

My question is this. If any of you have done self install did you use ferrels on the 4 awg wire inside the charger?

I was wondering the same thing. #4 is somewhat difficult to work with if you are not used to it. Using ferrels would make it a slightly cleaner install and easier. Finding the proper ferrels and especially the crimper may not make it worth the effort.

 

[zero610]

Other valid options would be 6 AWG in conduit which allows using the 75c rating which allows 65 amps. This is what I did. 60a breaker, 48a usable for my Model 3 LR.

Does this apply to MC cable? 6/2 (plus ground) THHN inside metal clad?

 

[1.21GW]

My decision has been made, going with 4/3 it will be installed next week! Thanks for the help. In the end, the cost of this installation pales in comparison to the options list on my car... and I would think charging is more important than white seats in the grand scheme of things. So, I chose the better wire for 48A charging and White seats too! What would I spend my money on if it wasn't for Tesla? (I'd probably do something responsible and save it..)

 

[eprosenx]

I was wondering the same thing. #4 is somewhat difficult to work with if you are not used to it. Using ferrels would make it a slightly cleaner install and easier. Finding the proper ferrels and especially the crimper may not make it worth the effort.

Ferrules are recommended in the installation instructions, but not required. I did not use them since I did not have the right tool, etc... I did make sure to properly tighten my terminals well though and to carefully insert the wire.

I was going to say that perhaps ferrules are more important toward the higher end of the amperage range (like if you were doing a 100a circuit), but I don't know. Perhaps they are more important on smaller gauge wires when placed under the large lugs that can accept 3 AWG or 2 AWG (I emailed Tesla Support and I think they told me 2 AWG was the max size the terminals will handle).

 

[eprosenx]

Does this apply to MC cable? 6/2 (plus ground) THHN inside metal clad?

My reading of the code is that MC cable is allowed to be utilized at the 75c rating. There is not the same language that exists in the section on NM cable that only lets you use the 60c rating. If I am not mistaken, AC cable did have a requirement to use the 60c rating if it is run in thermal insulation, but I did not see that in the MC section weirdly enough.

So yeah, MC 6/2 seems like a very easy to install and cost effective choice for HPWC installations if you can get it in the length you need (without having to buy several hundred feet...)

I ran mine in EMT which I think makes for a very bulletproof and clean looking installation, but that is quite a bit more work.

 

[GWord]

My question is this. If any of you have done self install did you use ferrels on the 4 awg wire inside the charger?

I have 2awg DLO cable into my HPWC and used ferrules. Way easier to get it into the lugs.

 

[zero610]

My reading of the code is that MC cable is allowed to be utilized at the 75c rating. There is not the same language that exists in the section on NM cable that only lets you use the 60c rating. If I am not mistaken, AC cable did have a requirement to use the 60c rating if it is run in thermal insulation, but I did not see that in the MC section weirdly enough.

So yeah, MC 6/2 seems like a very easy to install and cost effective choice for HPWC installations if you can get it in the length you need (without having to buy several hundred feet...)

I ran mine in EMT which I think makes for a very bulletproof and clean looking installation, but that is quite a bit more work.

Thanks for the info. I did the install myself also using 6/2 MC - just making sure I didn't undersize my wire. Very cheap DIY (spent less than $100 for materials, excluding the HPWC). You're right though, EMT will definitely look cleaner. If I ever need to rerun the wiring, I'll probably use that for a cleaner install.

 

[rdlink]

Ferrules are recommended in the installation instructions, but not required. I did not use them since I did not have the right tool, etc... I did make sure to properly tighten my terminals well though and to carefully insert the wire.

I was going to say that perhaps ferrules are more important toward the higher end of the amperage range (like if you were doing a 100a circuit), but I don't know. Perhaps they are more important on smaller gauge wires when placed under the large lugs that can accept 3 AWG or 2 AWG (I emailed Tesla Support and I think they told me 2 AWG was the max size the terminals will handle).

So you were able to get the 4 AWG into the terminals on the HPWC? My charger hasn't arrived yet, but I watched a video of the install, where the person who did the video used 6 AWG. I didn't see him actually install the wires, but they looked pretty snug.

 

[GWord]

So you were able to get the 4 AWG into the terminals on the HPWC? My charger hasn't arrived yet, but I watched a video of the install, where the person who did the video used 6 AWG. I didn't see him actually install the wires, but they looked pretty snug.

With judicious application of foul language, the HPWC terminals will accept 2AWG actually.

 

[SDRick]

Actually or eventually?

That's why they make ferrules.

 

[GWord]

Actually or eventually?

Yes.





I did find ferrules make the job a lot easier. Also finely stranded cable was helpful.

 

[eprosenx]

With judicious application of foul language, the HPWC terminals will accept 2AWG actually.

I may be mis-remembering this, but there might have been something about needing to use the top entry bracket that comes with the HPWC if you are going to use 3 awg or 2 awg. It may be easier to land the wires in that then directly on the HPWC.

Check me on that though. I am on my phone and don’t have my laptop handy. You can get the manual on the Tesla web site.

 

[GWord]

I may be mis-remembering this, but there might have been something about needing to use the top entry bracket that comes with the HPWC if you are going to use 3 awg or 2 awg. It may be easier to land the wires in that then directly on the HPWC.

Check me on that though. I am on my phone and don’t have my laptop handy. You can get the manual on the Tesla web site.

The top entry bracket comes with ferruled, finely stranded interconnect wiring so it could be a lot easier depending on what you are using for your home run back to your panel. The lugs in the HPWC itself definitely can accept larger AWG wires, it's just a pain to get it wired, especially if your installation is back entry and the wires make a weird bend. I think your confusion might stem from the fact that in the same paragraph in the manual, Tesla brings up the use of the top entry bracket and a sealing gland and then talks about using 2AWG wire for 80A installations. It sort of makes it sound like they are mutually inclusive but it's just badly written.

 

[SSonnentag]

If this is going into a home you own, spend the extra $200 and put in a 100A breaker, larger conduit and wire. EVs will only draw more power for charging from here on out. Might as well future-proof it when reasonable.

 

[Rocky_H]

If this is going into a home you own, spend the extra $200 and put in a 100A breaker, larger conduit and wire. EVs will only draw more power for charging from here on out. Might as well future-proof it when reasonable.

This is that fallacy I see too often here. People think that because a future electric car has twice the range, that it somehow equates that they now live twice as far from work and drive twice as many miles. That's not how that works.

You drive X amount of miles per day. It doesn't matter if the car has a capability of 100 miles or 1,000 in its battery, or if it can go 80 mph or 180 mph. The performance of the car doesn't affect how much you drive(generally). So you need a level of charging power at home that refills your X amount of miles in the amount of time that you have.

And if you do want to look at the effect of bigger and bigger batteries in the future, that would actually equal less need for faster and faster charging rates at home, since you won't be coming close to using up what you have in the battery and will have more left over, meaning less need to get it refilled quickly.

 

[SSonnentag]

This is that fallacy I see too often here. People think that because a future electric car has twice the range, that it somehow equates that they now live twice as far from work and drive twice as many miles. That's not how that works.

You drive X amount of miles per day. It doesn't matter if the car has a capability of 100 miles or 1,000 in its battery, or if it can go 80 mph or 180 mph. The performance of the car doesn't affect how much you drive(generally). So you need a level of charging power at home that refills your X amount of miles in the amount of time that you have.

And if you do want to look at the effect of bigger and bigger batteries in the future, that would actually equal less need for faster and faster charging rates at home, since you won't be coming close to using up what you have in the battery and will have more left over, meaning less need to get it refilled quickly.

Buy why would you intentionally design in a 10+ hour recharge time when you could half that for 10-15% more upfront cost? I have had to stop at a supercharger on my way home because I know that I won't have time to charge at home long enough to head out again. Planning ahead in your installation has real benefits. Sure, it isn't going to make a difference every time you charge, but why ignore the occasional benefits when the cost is so little up front?

 

[SSonnentag]

. . . besides, you may get a second or third EV some day. Now you've just double or tripled your charge time. Future-proofing is a winner every time.

 

[mongo]

. . . besides, you may get a second or third EV some day. Now you've just double or tripled your charge time. Future-proofing is a winner every time.

Then you would have 2-3 charge connectors, each with an appropriate circuit capacity (unless you are swapping multiple times). Also, It's not like every panel can even take a 100 amp feed...
I understand optimizing the investment, but 100 Amp may be a bit overkill unless putting in a garage sub panel.

 

[SSonnentag]

Then you would have 2-3 charge connectors, each with an appropriate circuit capacity (unless you are swapping multiple times). Also, It's not like every panel can even take a 100 amp feed...
I understand optimizing the investment, but 100 Amp may be a bit overkill unless putting in a garage sub panel.

So our planning ahead when we built our house and had solar installed was a good thing? 400A service was only $1100 more than 200A.

PS Multiple Tesla chargers can share a single power feed.

 

[mongo]

So our planning ahead when we built our house and had solar installed was a good thing? 400A service was only $1100 more than 200A.

I feel ya, 320 Amp meter here, came in handy when I built a barn.

PS Multiple Tesla chargers can share a single power feed.

Sure, but then you are splicing/ tapping the 100A wire vs having 3 60 feeds and inter WC communications.