DIY Home Improvement Forum banner

EV charger installation - check my work after hours of research.

621 Views 20 Replies 6 Participants Last post by  seharper
Alright, I've reached the end of my research and I just need people smarter than me to double check my work.

OVERVIEW:
New vehicle shopping, going to likely be a PHEV (volvo XC 60 recharge), but might go full EV. Outdoor install. I do want the "smart" features in a charger so I can track $ spent, and I want to future proof a bit.

WHAT I HAVE: I have a dedicated 240v 40amp spare circuit breaker in my garage panel that terminates randomly into my unfinished basement ceiling. This was new construction 6 years ago, I didn't request it, so I have no idea why it is there. The wire is Romex 8/3 wire w/ 10AWG ground.
Electrical wiring Gas Cable Electrical supply Wire


WHAT I PROPOSE: Buying a Grizzl-E Smart charger, setting the DIP switch to 32A to keep it safe for my 40A breaker, and hard wiring it with a short conduit run to get it up higher off the ground. I would drill a hole to the exterior to a outdoor rated junction box, take the romex 8/3 and splice it to 8 THHN in the junction box, and then a short conduit run straight up to hard-wire in the Grizzl-E. Cap the neutral in the box. See the picture below.

Plant Road surface Asphalt Grass Brick


THINGS I'VE THOUGHT ABOUT:
1) It's a short run from the breaker to the basement junction box. 10-15 feet max. So that isn't a long pull of Romex
2) Breaker is in the garage right inside of the door to the left in the picture so I don't see the need for a disconnect.

QUESTIONS:
1) Is this plan sound?
2) Anyone's recommendation for a favorite outdoor junction box welcomed
3) What conduit is the easiest to use for people that haven't used conduit before? Should be an easy short/straight run.
4) Is it code to have the romex come from the interior of the house immediately into a junction box to transition to THHN, or do I need to do that INSIDE the house with conduit through the exterior wall?
5) Things you would change or other ideas?

Thanks folks!
1 - 20 of 21 Posts

· Super Moderator
Joined
·
18,142 Posts
NM into the back of the box is fine. If the unit is hardwired it needs a disconnect.

PVC conduit into a PVC junction is easiest.
 

· Registered
Joined
·
25 Posts
Discussion Starter · #3 ·
NM into the back of the box is fine. If the unit is hardwired it needs a disconnect.

PVC conduit into a PVC junction is easiest.
Is this outdated information from the NC handbook? (I can only find the 2014 edition, nothing newer) https://pluginnc.com/wp-content/uploads/2016/06/19-ESVEHandbook_V4_final.pdf

For charging stations rated more than 60 amperes, a separate disconnect is required (NEC 625.23) and should be installed when running conduit. Some customers may desire a separate disconnect for stations rated below 60 amperes as well. A separate disconnect should be visible from the charging station
 

· Registered
Joined
·
893 Posts
Disconnect is no longer needed for the 32A level you are running. Up to you whether you install it. IMO it’s not necessary since these things don’t really need servicing, and the disconnect adds extra ugliness. Easiest conduit for that would probably be liquidtite (plastic version). No bending needed, all fittings you can buy are wet rated.
  • It would be limited to 60C since wet location (irrelevant because you are limited to 60C anyway by the NM, and I can’t think of a permutation of conductor choices where you want 75C).
  • Looks uglier
  • It may be rejected by AHJ due to “subject to damage”. Many hardwire EVSE come with whips that are also basically liquidtite…
Boxes with threaded holes already may be slightly easier, and IMO are easier to get water tight for the upward facing conduit you are adding. You can get with back hole and top hole.

Regarding equipment choice, GrizzlE has had some egg on their face for EVSE fires. They claim it is due to a bad batch. That said their terminals are not as nice as other manufacturers.

Make sure you buy a torque screwdriver for making terminal connections. And follow the instructions carefully.

For tracking the usage you could also use an energy monitor (I use Emporia) installed in the subpanel. This gets the usage info for the house centralized rather than having some in the EVSE and the others elsewhere. Though if you use something like homeassistant to aggregate energy usage info into one place this doesn’t matter as much.

For future proofing OCPP (GrizzlE has it) and possibly load sharing (I don’t think GrizzlE has it) if you want to go to two EVSE and are concerned about service size.

Make sure you buy a torque screwdriver for making terminal connections. And follow the instructions carefully.

Another option is to try to get the romex up the inside of that wall and into the back of a EVSE. I don’t believe GrizzlE has back entry option, and this requires more skill to pull off.
 

· Registered
Building my last home
Joined
·
5,468 Posts
Nice looking ride.

The one thing that you have not considered is your driving habits. With the hybrid not so much of an issue. The electric vehicle you might need those extra 8 amps for charging over night.%

The thing I have read about is that the LI chemistry used in cars is a bit different than the LI for everything else. There are articles about long term charging EV's all over the net. What I have noticed is most EV tests are done at 20-80%. There are articles that state it can take as many hours to get from 80-100% as it does from 20-80%. This is because of the LI charge cycle.

My neighbor has a older Ford Hybrid. He drives 60 miles a day. He charges with the 120v cord, because he is to cheap to put in a bigger charger. Over the last 2 years he has noticed a drop in battery capacity. He and I have talked about it and I attribute the issue to the only time the car ever has a full charge is after a weekend or 3 day holiday. Spending that much money on a vehicle I would want to know more about how not charging to 100% over time will effect the batteries.
LI is different than anything I have dealt with in my electrical career. I have worked on and taken care of large lead acid batteries for UPS's and the phone company (100-500 kw systems). Different tech I know, we always tried to keep the batteries very close to 100% charged. Also tried never to get below 50% capacity.

Thoughts from the cheap seats.
 

· Registered
Joined
·
893 Posts
The 80-100% slowdown is only for L3 fast charging. This is really important for road-trip planning but not relevant for daily charging at home.

For L2 charging I don’t believe there are many cars that will slow down between 80-100%.

If you look at the charge current you will see why. 10kW is a pretty beefy L2 charger these days. Compared to a car battery of 70-80kWh this charge rate is below 0.15C

Fast charging is done at 1-4C. Typically more in the middle of that range
 

· Registered
Joined
·
7,764 Posts
OP your first stop is to determine whether your house can handle an additional 40A on the Load Calculation, which is computed through the procedures in NEC Article 220. This provides a number of "fudge factors" to account for diversity of loads in a dwelling. EV charging doesn't get much of a "fudge factor" since it is a hard continuous load.

If not, you already know how to adjust the DIP switches or whatever to tell the EVSE to charge slower.

I know people (especially people new to EVs) have a lot of charge amp anxiety. Everyone knows it wouldn't be a Harper post if I didn't link this video :)


(cued up to 28:15).

My neighbor has a older Ford Hybrid. He drives 60 miles a day. He charges with the 120v cord, because he is to cheap to put in a bigger charger.
60 miles/day is a little much for 12A level 1 charging.

If the garage circuit is 120V/20A, your buddy could get the NEMA 5-20 dongle for that charger and run [email protected] That'll probably do it. Dongles are typically around $40. (the amp rate is set by a microchip in the plug, which is there so it can sense plug temperature, hence you can't just cut the plug off.)

Or if your buddy can come up with some 14/2 or 12/2 Romex they can put in a perfectly respectable 240V circuit and probably keep using the same travel unit (another dongle). That would give 90 or 120 miles in 12 hours. Fill the battery twice lol.

Yeah, a lot of people get. hung up on "there are only TWO choices, too-slow 120V/15A.... or.... "240V/50A that is SEVEN TIMES faster". No, no, no.
 

· Registered
Joined
·
893 Posts
@zanydroid can you cite the lack of need for a disconnect at that level?
NY’s NEC2017 version, I dont think they amended. You can search my forum posts, here and on Reddit, for a little more analysis.

Most residential EVSE are of this lower charge current. Majority of residential 208 and all 240 should satisfy the volts to ground too.

625.43 Disconnecting Means
For 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 lockable open in accordance with 110.25.

EDIT: I don’t see many disconnects on the installations I can see from streets. There is one really visible one for a Tesla, that has a nice knife disconnect on it. Seems overkill but I guess that should satisfy the lockable open rule.
 

· Registered
Building my last home
Joined
·
5,468 Posts
He plugs it into a 20 amp I put under his panel. I would have done a bigger one for free if he would pay for the parts.
 

· Registered
Joined
·
7,764 Posts
EDIT: I don’t see many disconnects on the installations I can see from streets.
Yeah, you can't go by what EVers actually do... EV communities are a huge echo chamber where misconceptions (starting with "need a 50A socket") get repeated louder and louder, and everyone has the singular goal of getting it "working" regardless of how. You see the same "safety trampled by lemmings" problem with dimmers on switch loops, generator hookups, etc.
 

· Registered
Joined
·
25 Posts
Discussion Starter · #13 ·
DONE!

Plant Building Wood Lighting Window


NOTE: It was too cold to get the liquid tight flexible conduit to cooperate...even with a heat gun. A final tidy-up/security clamp install will happen on a warm/sunny day.
My installation is to an existing spare 40a breaker, so the Grizzl-E was internally setup to 32a max via the DIP switches as described in the manual. Super easy.
I had 8/3+10g Romex in the interior, drilled a hole in the wall, installed an outdoor rated junction box + cover, and used polaris connectors to take the 8/3 romex to 8 AWG THWN in the conduit (10 AWG for the ground). I did use a wire nut for the ground 10AWG wire to save on costs (and it is small enough that a wire nut can handle it). You won't use the white wire in the Romex, so it was capped.
The conduit size is 3/4inch. I measured the opening in the Grizzl-E after removing the plug that came with it and it was 1inch. Turns out conduit is "named" by ID not OD, so after a trip to the hardware store buying 1inch conduit and realizing it was too big I went back to get the 3/4inch. I'm an idiot/noobie...save yourself a trip. I was able to use a shitload of strength to get the 3/4in flex into the opening and re-use the Grizzl-E's stock conduit connector fitting...but it was difficult.
For hardwiring the Grizzl-E, you need terminal connectors. I ordered this kit here because the Grizzl-E hardwiring instructions didn't give specifics: https://www.amazon.com/dp/B09JF3PN7K?ref=ppx_yo2ov_dt_b_product_details&th=1
The connectors were secured to the wire using this cheap hammer crimping tool: https://www.amazon.com/dp/B07DBQZPNJ?psc=1&ref=ppx_yo2ov_dt_b_product_details
I THINK I used the SC10-6 for the 8AWG wire and the SC6-6 for the 10AWG ground (notice the beer in the installation picture). Maybe down one size...but just order the kit to be safe and make sure you have everything you need.
Make sure not to over-tighten your connections in the Grizzl-E. Torque specs are listed in the Grizzl-E manual, and it's a wimpy amount of torque required. This is the running theory about the fires you read about with the Grizzl-E (over-torqueing).
From there it was run the wires into the conduit/junction box, make your splices, and seal things up.

Came out as good as I could have hoped. Just some conduit management in the future.
The Grizzl-E smart features are a bit lacking, but at least I can track the kwh put into the car so I can set power bill expectations. That was my main goal, so mission accomplished. Hopefully they improve the software with time.
Hope this helps someone.
 

· Registered
Joined
·
308 Posts
Interesting reading this, as well as the Tesla installation directions. My situation is simpler because everything is inside, and both the garage subpanel and the connection location are on the same wall, so I think the breaker can act as a disconnect (is that accurate?).
 

· Registered
Joined
·
25 Posts
Discussion Starter · #15 ·
Interesting reading this, as well as the Tesla installation directions. My situation is simpler because everything is inside, and both the garage subpanel and the connection location are on the same wall, so I think the breaker can act as a disconnect (is that accurate?).
I've read conflicting information, and I just went with the "I am literally feet from the panel so I'm calling it good enough" approach. I don't plan on selling this house anytime before I die so I won't have to worry about it.
 

· Registered
Joined
·
7,764 Posts
As long as your Load Calculaton can support it, 40A is a good midrange choice (between the urge to go huge, and actual need). This will support 200 miles per 10 hour of charge for normal vehicles, and 100-150 for a monster like a Hummer EV. More than you'll ever need. It will also support 200 miles for 2 vehicles with Power Sharing if/when you get to that point.

Make sure not to over-tighten your connections in the Grizzl-E. Torque specs are listed in the Grizzl-E manual, and it's a wimpy amount of torque required. This is the running theory about the fires you read about with the Grizzl-E (over-torqueing).
It's not a theory. It's hard science which was fully developed. As a result, after much heel-dragging and resistance by electricians who find it inconvenient, it finally went into NEC 110.14 in the 2014 edition (well before EVs took off in earnest). This should be nothing new to EVers. If scuttlebutt in the EV community is that "this is only a suggestion" or "something they are discovering", that is disappointing and reflects badly on the community. Surely someone in those communities knows this and speaks up. Are they simply ignored, silenced or canceled?

The perception of "wimpy" really depends on the tool. "Wimpy" on a ratchet will seem Hulk-tight on a screwdriver.

For hardwiring the Grizzl-E, you need terminal connectors. I ordered this kit here because the Grizzl-E hardwiring instructions didn't give specifics: https://www.amazon.com/dp/B09JF3PN7K?ref=ppx_yo2ov_dt_b_product_details&th=1
Mistake. That is cheap Chinese garbage off Amazon, and a code violation since it is not UL Listed. Your friendly neighborhood electrical supply house stocks appropriate lug connectors for under a dollar that use a setscrew (no crimp needed).

Never order electrical gear on Amazon Marketplace. (when "Sold By" is not Amazon; that's 3rd party sellers that are selling eBay tier crud).
 

· Registered
Joined
·
25 Posts
Discussion Starter · #17 ·
As long as your Load Calculaton can support it, 40A is a good midrange choice (between the urge to go huge, and actual need). This will support 200 miles per 10 hour of charge for normal vehicles, and 100-150 for a monster like a Hummer EV. More than you'll ever need. It will also support 200 miles for 2 vehicles with Power Sharing if/when you get to that point.



It's not a theory. It's hard science which was fully developed. As a result, after much heel-dragging and resistance by electricians who find it inconvenient, it finally went into NEC 110.14 in the 2014 edition (well before EVs took off in earnest). This should be nothing new to EVers. If scuttlebutt in the EV community is that "this is only a suggestion" or "something they are discovering", that is disappointing and reflects badly on the community. Surely someone in those communities knows this and speaks up. Are they simply ignored, silenced or canceled?

The perception of "wimpy" really depends on the tool. "Wimpy" on a ratchet will seem Hulk-tight on a screwdriver.
You must be a blast at parties!
 

· Registered
Joined
·
25 Posts
Discussion Starter · #19 ·
Lol. I was mostly referring to the rant about the comment to just make sure you follow torque recommendations.

I do appreciate the input on the connectors and I did have another suggestion somewhere else to cut into them and make sure they're not just copper plated aluminum. That's on the to do list. I just assumed everything is made in China and it didn't matter... But good information for anyone else coming behind me.

Long the day at work so I apologize for coming off snarkier than I should have.

I will report in if these connectors are sketchier than anticipated.

Cheers!
 

· Registered
Joined
·
893 Posts
Everything is made in China but there’s a big difference in first grade stuff made with auditing and supervision by a company with an NRTL or other such listing on the line…

vs seconds/thirds, randomly outsourced 5 layers deep or fell off a truck stuff that then shows up on AliExpress or Amazon with no brand name (or counterfeit packaging)

Also don’t forget about branded Shenzhen based companies like DJI that are pretty up there in capability and command a premium price, these are several ticks up the food chain vs the shovelers of Chinese crap.
 
1 - 20 of 21 Posts
Top