Sanity check request for OUTDOOR DIY installation of EVSE

[shikataganai]

Could any of you who have electrical experience sanity check this proposed outdoors EVSE wiring setup?

- Leviton EVB40-SPT 40A 240V EVSE, again to be mounted on the outside of the house
- 50 Amp non-GFCI breaker at the box (after upgrading service to allow for this, if necessary)
- 6/2 NM-B cable from said breaker to an LB junction box on the inside wall of the garage
- Within junction box splice the two wires + ground of the NM-B to two 6 gauge THHN/THWN-2 wires plus one additional 10 gauge wire as the ground
- Run said THHN wiring within a 1" metal conduit out through the garage's/house's wall to another sealed/waterproof LB junction box surface mounted on the outside of the house
- Another short run of 1" metal conduit upwards to the underside of the EVB40, to which the conduit will be secured and sealed
- Aforementioned THHN wiring, now safely and waterproofed-ly within the EVSE case, will finally be hard-wired--no receptacle involved in this chain as it'll be an outside installation, again

 

[shikataganai]

Diagram from EVB40 installation guide showing the conduit entrance for hard-wired setups on the bottom left of the unit as you face it:

 

[shikataganai]

Answers to anticipated questions:

1) Why a 50A breaker? 1.25x upsizing for continuous loads per code.
2) Why outside the house? Mother-in-law's house, and the garage isn't really big enough for two vehicles. She parks her ICE-mobile inside.
3) Why NM-B for the indoor run? To avoid running conduit all around the garage if I don't have to. I could simply staple NM-B cable to the exposed garage rafters, easy.
4) Why metal conduit for the outdoor run? The bottom H100-TB hub on the EVSE mates with 1" metal conduit, as best as I can tell. Might as well stick with it.
5) Why a 40A EVSE? Why not?
6) Why a non-GFCI breaker? Per Leviton, their 240V EVSE does not need to be on a GFCI protected circuit.
7) Why 6/2 cable instead of 6/3? See wiring diagram for the EVSE below. Only need two hot wires + ground. No neutral.

 

[garygid]

Are you planning on getting a permit for this work?

That is strongly recommended, to avoid hassles,
making sure that you follow local code, and tainting
the house with non-inspected wiring, which might
have to be disclosed when selling the house?

Local practices might not allow the 50 amp breaker,
just as an example. Also, a shut-off near the EVSE
(right under it in your case, in place of the external
junction box perhaps) might be a good idea, or even
"required" by local codes or practices.

In most jurisdictions, the planning/building/permit
department is there to help you, especially if you
ask nicely for their advice, and come well prepared.

You need to submit the documentation for the EVSE,
a drawing of what you intend to do, and get the
permit approval before you do the work, and then
an inspection before you put it into service.

The fee is usually small and includes checking your
plans, and the inspection of your work.
A professional would do an evaluation of the
loading of the circuit breaker box, which the
inspector might repeat before approving the job.

 

[shikataganai]

Seattle requires a permit, but Level 2 EVSE installations explicitly do not require plan submission or review. An inspection after permitting and construction is required before Seattle City Light will sign off on the new circuit.

I'll look into the 50A and external disconnect issues.

 

[DaveinOlyWA]

Seattle requires a permit, but Level 2 EVSE installations explicitly do not require plan submission or review. An inspection after permitting and construction is required before Seattle City Light will sign off on the new circuit.

I'll look into the 50A and external disconnect issues.

pretty sure "any" outside wiring requires plan, drawings, etc with permit application. in garage is different story. would also question the 50 amp breaker as well. 40 is all you need and is easily replaceable if future upgrades are planned. hesitate to venture a guess on the permit costs but my sis put a plug outside that I use to charge my LEAF with and the permit was $65 but that is in Oly and the price difference could be extreme

 

[QueenBee]

Are you planning on getting a permit for this work?

That is strongly recommended, to avoid hassles,
making sure that you follow local code, and tainting
the house with non-inspected wiring, which might
have to be disclosed when selling the house?

Local practices might not allow the 50 amp breaker,
just as an example. Also, a shut-off near the EVSE
(right under it in your case, in place of the external
junction box perhaps) might be a good idea, or even
"required" by local codes or practices.

In most jurisdictions, the planning/building/permit
department is there to help you, especially if you
ask nicely for their advice, and come well prepared.

You need to submit the documentation for the EVSE,
a drawing of what you intend to do, and get the
permit approval before you do the work, and then
an inspection before you put it into service.

The fee is usually small and includes checking your
plans, and the inspection of your work.
A professional would do an evaluation of the
loading of the circuit breaker box, which the
inspector might repeat before approving the job.

I would guess most jurisdictions will NOT require spec sheets, plans, and plan review to get an EVSE install permit. Here it's as easy and requesting it online with no documentation and then calling for inspection when it's complete. It's definitely recommended to get a permit though. Here is my city's handout on EVSE permitting: http://www.ci.bellevue.wa.us/pdf/Development%20Services/B-4_EVchargestation.pdf" onclick="window.open(this.href);return false;

Check the 6/2 NM-B you are buying, you might be surprised to find that the wires inside are actually THWN with printing indicating this. I'm not sure if this is universal among all brands but the 6/2 NM-B I have is in fact labelled as THWN. If this is the case the nice thing is then you don't have to splice the wires in the junction box and can then take it all the way to inside the EVSE. Much better to not have to splice it.

Depending on how comfortable you are working with rigid/imc you might consider just PVC for such a short conduit. Will be cheaper as well since the watertight connectors aren't cheap. The bottom of the EVSE will have a 1 inch trade size knockout and the 1 inch PVC threads will be the same size. You might also check to see if the knock out is also 3/4" or 1/2" because you only need 1/2" conduit for 2x #6 THWN and 1 bare #10 ground.

IMO having a disconnect next to your proposed install seems really excessive. If you are getting it permitted ask your inspector ahead of time if you need this. If they want you to have a disconnect see if the panel offers the option of individual breaker handle locks for example this one is common on GE panels around here: http://www.galesburgelectric.com/GE-THP100-Padlocking-Handle-Lock.html" onclick="window.open(this.href);return false;

Around here panel load calculations don't seem to matter much. I was worried I would have to replace my 1969 split bus 125 amp GE panel when Ecotality installed my EVSE but they and the inspector didn't seem concerned at all. Ended up replacing it anyway for solar PV but wasn't ready at the time.

No idea what local practices would not allow a 50 amp breaker? I can't think of any reasons why they would instead require a 60 amp breaker.

IMO sounds like you've got a good plan!

 

[QueenBee]

Seattle requires a permit, but Level 2 EVSE installations explicitly do not require plan submission or review. An inspection after permitting and construction is required before Seattle City Light will sign off on the new circuit.

I'll look into the 50A and external disconnect issues.

pretty sure "any" outside wiring requires plan, drawings, etc with permit application. in garage is different story. would also question the 50 amp breaker as well. 40 is all you need and is easily replaceable if future upgrades are planned. hesitate to venture a guess on the permit costs but my sis put a plug outside that I use to charge my LEAF with and the permit was $65 but that is in Oly and the price difference could be extreme

Obviously every jurisdiction is different but the City of Bellevue specifically does not require plan reviews on adding 120 or 240 volt receptacles and also specifically says they are not required for EVSE installs. I doubt your sister had to have a plan review to add a receptacle for you.

shikataganai note that you'll want to work with the City of Seattle DPD and not Seattle City Light on getting the permit and inspection.

 

[QueenBee]

Looking for a similar tip sheet for City of Seattle I found this simple pre assessment for an EVSE that it appears a homeowner is supposed to fill out to determine if they might have issues installing an EVSE. Doesn't sound like it's actually required to be completed.

http://www.seattle.gov/dpd/static/Preliminary%20Assessment%20of%20Single-Family%20Home%20Electrical%20Vehicle%20Capability_LatestReleased_DPDD017445.xlsx" onclick="window.open(this.href);return false;

Electrical permits for a Level II Charger (30 amp) require no plan review and may be obtained on-line or over-the-counter at DPD’s Applicant Service Center (ASC).

http://www.seattle.gov/DPD/Publications/CAM/cam132.pdf" onclick="window.open(this.href);return false;

I think they just need to update their article to be more generic since I'm sure they are not implying that a 16 or 40 amp EVSE do require a plan review.

 

[shikataganai]

Check the 6/2 NM-B you are buying, you might be surprised to find that the wires inside are actually THWN with printing indicating this. I'm not sure if this is universal among all brands but the 6/2 NM-B I have is in fact labelled as THWN. If this is the case the nice thing is then you don't have to splice the wires in the junction box and can then take it all the way to inside the EVSE. Much better to not have to splice it.

I'm not sure I would consider your proposed conduit run with water tight fittings to be a wet location so you could probably even run normal romex that doesn't have the THWN printings on it through your short conduit.

Depending on how comfortable you are working with rigid/imc you might consider just PVC for such a short conduit. Will be cheaper as well since the watertight connectors aren't cheap. The bottom of the EVSE will have a 1 inch trade size knockout and the 1 inch PVC threads will be the same size. You might also check to see if the knock out is also 3/4" or 1/2" because you only need 1/2" conduit for 2x #6 THWN and 1 bare #10 ground.

IMO having a disconnect next to your proposed install seems really excessive. If you are getting it permitted ask your inspector ahead of time if you need this. If they want you to have a disconnect see if the panel offers the option of individual breaker handle locks for example this one is common on GE panels around here: http://www.galesburgelectric.com/GE-THP100-Padlocking-Handle-Lock.html" onclick="window.open(this.href);return false;

Around here panel load calculations don't seem to matter much. I was worried I would have to replace my 1969 split bus 125 amp GE panel when Ecotality installed my EVSE but they and the inspector didn't seem concerned at all. Ended up replacing it anyway for solar PV but wasn't ready at the time.

No idea what local practices would not allow a 50 amp breaker? I can't think of any reasons why they would instead require a 60 amp breaker.

IMO sounds like you've got a good plan!

Thanks for the feedback so far, everyone.

Dave in Olympia: On the Seattle DPD website I didn't see a distinction made for indoor vs outdoor EVSE permits. There is the odd 30A language as pointed out one post up.

WRT NM-B in conduit: I thought that was frowned upon. Perhaps 1" would be enough for adequate cooling. Also I'm not sure if NM-B even if it is comprised of THWN wires is kosher outdoors, whether or not in conduit. I'd rather splice at the inside box than run UF cable the whole distance.

Thanks for the PVC tip. I wasn't sure if 1" thread size for PVC was the same as for metal.

WRT disconnects, this is from the Seattle electrical code. I'm not sure whether my install would fall under its purview:

ARTICLE 225
Outside Branch Circuits and Feeders

225.32 Location. The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in 230.6 shall be utilized.

FPN: WAC 296-46B-225.032 regarding the location of outside feeder disconnecting means is by this reference made part of the 2008 Seattle Electrical Code.

Exception No. 1: For installations under single management, where documented safe switching procedures are established and maintained for disconnection, and where the installation is monitored by qualified individuals, the disconnecting means shall be permitted to be located elsewhere on the premises.

WRT breaker size: I think some people were suggesting a 40A breaker, not 60A. I don't understand why.

Finally, with regard to panel load, Seattle code says for less than four EV charging bays one can assume 50% usage, for what that's worth. I'm hoping there will be unused capacity on the board as it stands since the house has a now-unused hot tub that may have had its own 240V circuit...

 

[QueenBee]

Dave in Olympia: On the Seattle DPD website I didn't see a distinction made for indoor vs outdoor EVSE permits.

WRT NM-B in conduit: I thought that was frowned upon. Perhaps 1" would be enough for adequate cooling.

Thanks for the PVC tip. I wasn't sure if 1" thread size for PVC was the same as for metal.

WRT disconnects, this is from the Seattle electrical code. I'm not sure whether my install would fall under its purview:

WRT breaker size: I think some people were suggesting a 40A breaker, not 60A. I don't understand why.

Finally, with regard to panel load, Seattle code says for less than four EV charging bays one can assume 50% usage.

It's pretty clear that with regards to breaker size for a continuous load (which an EVSE is) that it needs to be at least 125% of the continuous load (Unless a breaker that is rated for 100% is used which isn't likely for a residential breaker) so I think anyone suggesting that a 40 amp EVSE be put on a 40 amp breaker is incorrect.

NM-B can be put in conduit when it is being used to protect it, for example if you were running NM-B on the outside of the drywall in your garage you could run the NM-B down from the ceiling in conduit to protect it from damage. Additionally if your #6 NM-B is THWN you can strip the sheath off and just pass the THWN through the wall. And then for runs of conduit less than 24" are considered nipples so you can fill them to 60% compared to the normal 40% and the rules on derating because of heat don't apply. So assuming the knockout on the EVSE has multiple sizes you can easily use 1/2" or 3/4" conduit.

As for the disconnect I believe this would be the code section that would require one from 2008 NEC 422.31 (B)

422.31 Disconnection of Permanently Connected
Appliances.
...
(B) Appliances Rated over 300 Volt-Amperes or 1/8 Horsepower. For permanently connected appliances rated over 300 volt-amperes or 1/8 hp, the branch-circuit switch or
circuit breaker shall be permitted to serve as the disconnecting means where the switch or circuit breaker is within sight from the appliance or is capable of being locked in the open position. The provision for locking or adding a lock to the disconnecting means shall be installed on or at the switch or circuit breaker used as the disconnecting means
and shall remain in place with or without the lock installed.

 

[davewill]

It's pretty clear that with regards to breaker size for a continuous load (which an EVSE is) that it needs to be at least 125% of the continuous load (Unless a breaker that is rated for 100% is used which isn't likely for a residential breaker) so I think anyone suggesting that a 40 amp EVSE be put on a 40 amp breaker is incorrect.

I think some people got confused because 30a EVSEs are the most common, and some EVSEs are named for the size of the circuit, not the amperage that the J1772 supplies. For instance, the Clipper Creek LCS-25 needs a 25a circuit and delivers 20a. In this case, the Leviton EVB40 actually delivers 40a (9.6 kW) and requires a 50a circuit.

Dollars to doughnuts (which isn't really a lopsided bet these days), that a disconnect will be needed, and I think I would put one in anyway. There just always seems to be situations where you need to reset these things, plus it would be nice to be able to work inside of it without traipsing all the way to the main circuit breaker.

 

[QueenBee]

It's pretty clear that with regards to breaker size for a continuous load (which an EVSE is) that it needs to be at least 125% of the continuous load (Unless a breaker that is rated for 100% is used which isn't likely for a residential breaker) so I think anyone suggesting that a 40 amp EVSE be put on a 40 amp breaker is incorrect.

I think some people got confused because 30a EVSEs are the most common, and some EVSEs are named for the size of the circuit, not the amperage that the J1772 supplies. For instance, the Clipper Creek LCS-25 needs a 25a circuit and delivers 20a. In this case, the Leviton EVB40 actually delivers 40a (9.6 kW) and requires a 50a circuit.

Dollars to doughnuts (which isn't really a lopsided bet these days), that a disconnect will be needed, and I think I would put one in anyway. There just always seems to be situations where you need to reset these things, plus it would be nice to be able to work inside of it without traipsing all the way to the main circuit breaker.

Ah, that's a little bit of deceptive marketing.

I agree for things in hard to reach places like a roof or attic but I just dislike the extra cost, extra 8 connections that can fail, extra box and conduit exposed, and extra wire needed for something that can also be achieved by an $8 handle lock on the breaker. In cases where there are moving parts like in HVAC I can see why they are required both for electrical safety but also mechanical safety. Anyway, I just think the handle lock creates a cleaner install even if it means you have to walk around the corner into the garage to disconnect the EVSE when servicing it.

If you do decide to add a disconnect you should be able to find one that can handle 50 amps for less than $10.

Another consideration is there have been a lot of professional installations that are permitted which use a receptacle and a weather resistant cover on outside installs.

 

[DaveinOlyWA]

the real takeaway here is to check your local codes. my install was different in that it was simply a plug, not an EVSE so potentially anything could use it as long as the plug fit.

I had to get watertight boxes and a GCFI circuit breaker for the 240 volt plug (up until that point, I never knew they existed and they are EXPENSIVE!) I was advised that the same install in a garage would have been completely different.

 

[wwhitney]

I'm not sure I would consider your proposed conduit run with water tight fittings to be a wet location so you could probably even run normal romex that doesn't have the THWN printings on it through your short conduit.

The interior of conduit in a wet location is itself considered a wet location. So no NM cable in exterior conduit.

WRT NM-B in conduit: I thought that was frowned upon.

There's nothing wrong with doing that, it is just that it is usually trouble because you have treat the cable as having a circular cross section of diameter equal to its biggest dimension, and then meet the conduit fill requirements.

Cheers, Wayne

 

[shikataganai]

if your #6 NM-B is THWN you can strip the sheath off and just pass the THWN through the wall.

I'm not convinced that stripping NM-B cable and using the individual wires past a certain point is kosher. I'd rather play it straight and splice at a junction box, or run unmolested UF the whole way (see immediately below).

Splicing NM-B to THHN seems like it'd be pretty straightforward with something like this:

Morris 97354 multi-cable connector

The interior of conduit in a wet location is itself considered a wet location. So no NM cable in exterior conduit.

Thanks for the confirmation. I could run 6/2 UF the whole way, I suppose, as the cable isn't that much more expensive after accounting for splice hardware that I wouldn't need. Stripping UF seems like it'd be a royal pain in the ass, though, and the handy quick stripping tools aren't designed for outlier 6 gauge wire!

I just dislike the extra cost, extra 8 connections that can fail, extra box and conduit exposed, and extra wire needed for something that can also be achieved by an $8 handle lock on the breaker.

Duly noted. I shall plan to use a breaker with a handle lock as you recommend. This EVSE will be on the outside wall not 20 feet as the crow flies from the breaker itself.

my install was different in that it was simply a plug, not an EVSE so potentially anything could use it as long as the plug fit.

Another consideration is there have been a lot of professional installations that are permitted which use a receptacle and a weather resistant cover on outside installs.

Leviton says that outdoors installations of their EVSE has to be hard wired, no ifs, ands, or buts. On the other hand, I wonder how valid the warranty would be if they found out that I, not a licensed electrician by any stretch of the imagination, did the installation. :shock:

 

[QueenBee]

if your #6 NM-B is THWN you can strip the sheath off and just pass the THWN through the wall.

I'm not convinced that stripping NM-B cable and using the individual wires past a certain point is kosher. I'd rather play it straight and splice at a junction box, or run unmolested UF the whole way (see immediately below).

Just to clarify what I mean. I don't want to use absolutes so I can't I say this applies to all or even most #6 NM-B sold, just the wire I've used. On mine the actual wires inside are fully marked as being THWN. If the wire you buy also has these marking there is no issue passing it through the conduit since it's clearly marked for the this use.

I will however retract my comment about doing it if it was unmarked.

If you end up needing to splice in the junction box it's probably best to just use blue wire nuts like these: http://www.idealindustries.com/prodDetail.do?prodId=30-454&div=0&l1=twist-on" onclick="window.open(this.href);return false;

From here model 454 supports 1 or 2 #6 : http://www.idealindustries.com/media/pdfs/products/references/ideal_ul_listed_combinations.pdf" onclick="window.open(this.href);return false;

Another consideration is there have been a lot of professional installations that are permitted which use a receptacle and a weather resistant cover on outside installs.

Leviton says that outdoors installations of their EVSE has to be hard wired, no ifs, ands, or buts. On the other hand, I wonder how valid the warranty would be if they found out that I, not a licensed electrician by any stretch of the imagination, did the installation. :shock:

Yeah, it's pretty clear to me that if you follow the rules and instructions this is not OK but Ecotality paid electricians did it left and right, and the inspectors passed it.

 

[QueenBee]

I'm not sure I would consider your proposed conduit run with water tight fittings to be a wet location so you could probably even run normal romex that doesn't have the THWN printings on it through your short conduit.

The interior of conduit in a wet location is itself considered a wet location. So no NM cable in exterior conduit.

Thanks for calling me out on that. So how does this apply to other scenarios. For example say the NM-B goes through the wall into a disconnect, or a weather rated metal junction box, or if that junction box also has a receptacle in it, all mounted to the outside wall. Are these considered damp/wet and thus NM-B should not enter them?
I ask because I did all three of those things on my heat pump install. Inspector didn't really look too closely but didn't seem to have a problem with it.

What if it the NM-B went directly into the EVSE from the rear?

 

[shikataganai]

What if it the NM-B went directly into the EVSE from the rear?

I was wondering about this exact scenario before finding the Leviton installation instructions that depicted that the conduit should be connected from below.

For the curious, said instructions are linked in turn from the following link, as it was non-trivial to locate them:

http://www.leviton.com/OA_HTML/SectionDisplay.jsp?section=43380&minisite=10251" onclick="window.open(this.href);return false;

 

[UBUYGAS]

The only hiccup I had when I installed mine is that the Mounting Bracket template calls for 5" min clearance from anything that is above the charging station; but when I received the EVB40-SPT it needed around 10" of vertical clearance. The mounting bracket was initially designed for the units that came out in 2010 and those did not have the plastic housing like this new unit has. The plastic housing adds 5" of extra vertical height to the EVB40-SPT.

So in order to mount the unit on the bracket I had to remove a strip of wood that was above the mounting bracket on my wall.

You can see what I mean here:

Could any of you who have electrical experience sanity check this proposed outdoors EVSE wiring setup?

- Leviton EVB40-SPT 40A 240V EVSE, again to be mounted on the outside of the house
- 50 Amp non-GFCI breaker at the box (after upgrading service to allow for this, if necessary)
- 6/2 NM-B cable from said breaker to an LB junction box on the inside wall of the garage
- Within junction box splice the two wires + ground of the NM-B to two 6 gauge THHN/THWN-2 wires plus one additional 10 gauge wire as the ground
- Run said THHN wiring within a 1" metal conduit out through the garage's/house's wall to another sealed/waterproof LB junction box surface mounted on the outside of the house
- Another short run of 1" metal conduit upwards to the underside of the EVB40, to which the conduit will be secured and sealed
- Aforementioned THHN wiring, now safely and waterproofed-ly within the EVSE case, will finally be hard-wired--no receptacle involved in this chain as it'll be an outside installation, again