How to Require New construction to Pre-Wire for EV's???

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TRONZ

Well-known member
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Sep 22, 2010
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I sit in the camp that public L2 charging is necessary for early EV's but will become unnecessary as ranges increase. So looking ahead a few years people will be charging at home for a 200 mile range and using L3 for road trips. I am very interested in how new home construction should include pre-wiring for EV's. The entire system is not necessary, such as EVSE, second meter, etc. But Requiring empty conduit, J-boxes and stub outs in the right locations is a minimum that should be adopted into the Electrical Code. The ease and cost of doing this work during new construction is incredibly cheap and fast. There are already endless requirements that must be met in the Codes and builders meet them every day. How do we get EV Pre-Wiring added as a new requirement???
 
City of Irvine required my home to have 40a EV circuit installed.
Panel breaker is marked EV and was terminated with a 10-50R.
Home was finished in 2004 so it must have been on the books since at least 2003 or before.
 
This kind of thing seems more suited for the building code, rather than the electric code.

But the easiest way to get EVSE-ready homes would be to work with the property owners, designers and builders. Especially for places that might not have garages, like condo and apartment complexes. It would probably be easier to make a case to them to include empty conduit and j-boxes than it would to have something codified... if only because changing the code for any reason takes forever and a day.
=Smidge=
 
One related question: Does it make sense to use a thicker gauge of wire than the minimum required (currently 8 AWG for up to 40a 240v), both to anticipate future higher charge rates (the NEC code currently requires 6 AWG up to 55a 240v) but also to have higher efficiency due to reduced reduced electrical resistance in the wire (= I squared times R)?
 
MikeD: Yes. As we get cars with bigger batteries, either the current needs to go up, or charge times will increase to unacceptable levels. The Tesla roadster can already use the size wiring you're contemplating. I don't think that there is the slightest doubt that bigger will be better.
 
So, if one is upgrading (or specifying) sufficient service for the future, considering charging 1 (or 2) EVs, would a 400-amp service be better than 200?

Or, are there other options or suggestions to consider?
 
a 400A residential service is quite expensive, and not "normal". the standard for residential is 200A or in some cases a 225A service. typically, 400A service is reserved for multitenant houses/condos.

I think a standard 200A service will be just fine. If you have to 2 EV's, one can use a higher current charger such as an 80A circuit, while the 2nd one uses a standard 30-40A circuit, since they will be charging later in the evening, your Air Conditioning will have to be set to be off, and if you happen to have electric heat, that will need to be set so that is off as well during times when the charging is occuring. Same thing if you have any other large electrical loads, make sure they are off during the overnight charging window.

BTW, it's probably best to just specify the location(s) in the garage & the height above the finished floor (AFF), for the outlet/junctionbox, and that they have 1" or 1 1/4" PVC or EMT conduit running from the 1 or 2 locations to the breaker panel (most of them are located in the garage anyway, on new construction). If the empty conduits are installed, it's very simple to just pull the wire size you need and install the breaker, if the homeowner actually NEEDS an EVSE later.
having the builder pull the wire and install the breaker almost gurantees a lot of extra cost, that may not be needed, and whatever wire size/breaker is used, won't be "right" for that user... a 1-1 1/4" conduit should handle anything needed.
 
When the guys are out roping a new house the cost of the #8 romex for one or two extra circuits is probably less than pulling in a separate team to actually fit the house with some empty conduit.
 
LTLFTcomposite said:
Government intrusion

In fact you could say that about the entire building code and every law the U.S. has. It took a law to get seat belts put in cars. Don't use em if you don't want to but every time I strap my kids in, I thank god for this Govenment Intrusion :roll: .

I would think that either empty conduit or #8 wire would be fine as long as they provide a run. I am also running up against a clearance issue for a second meter so having extra clearances required around them would be helpful. What other common issues are people running into?
 
smkettner said:
When the guys are out roping a new house the cost of the #8 romex for one or two extra circuits is probably less than pulling in a separate team to actually fit the house with some empty conduit.

Yes, then you are limited to a 40A MAX EVSE, without replacing the wire and circuit breaker.

It's very easy to install PVC pipe when all of the walls are open, just means drilling a few holes, and installed some nail plate protectors, it's not that difficult, and any electrician or plumber can do it.
 
Questions, Please:

When can one use PVC conduit vs, metal conduit for electrical wiring?

Is there a thin-wall "electrical" PVC "pipe" (rigid, or flexible?) so that the holes in the studs do not need to be so large?

In 1.25" PVC conduit, is that the ID?
What is the OD?
 
When can one use PVC conduit vs, metal conduit for electrical wiring?

In general either one can be used, it's far easier to use PVC when running pipe "inside" of walls, when you run PVC pipe, you of course must include a separate ground conductor, where in some cases, eletrical inspectors allow the EMT pip to be used as ground (some still require the ground conductor anyway)

Is there a thin-wall "electrical" PVC "pipe" (rigid, or flexible?) so that the holes in the studs do not need to be so large?

PVC comes in different "schedules", schedule 80 is generally used for outdoor/hardended installation work (underground feeders for example), schedule 80 pipe has 1/4" walls. most electrical work is done with schedule 40 PVC. PVC is "rigid", but there are 90, 45, 30 and 22.5 degree "sweeps" available, so it's easy to buy premade bends, and just glue it all together like a giant "lego" setup, the limitation is, you cannot use "lb"'s (Elbows), with covers inside of walls, because they would not be "accessable", you would need to mount a 4" x 4" electrical box to make a 90 degree tight turn, or just use a "90 degree sweep". Also, in general you want to have less than 270 degree's of turns, for a single pull.

In 1.25" PVC conduit, is that the ID?
What is the OD?


when discussing pipe size for electrical use, ID (Inside Dimensions) are used. Schedule 40 PVC is 1/8" walls, if memory serves me correct.
http://www.engineeringtoolbox.com/pvc-cpvc-pipes-dimensions-d_795.html
 
garygid said:
When can one use PVC conduit vs, metal conduit for electrical wiring?

You will absolutely want to talk to someone who knows the local codes. Some codes allow PVC electrical conduit indoors, others require metallic conduit if you use conduit at all.

Also note that PVC electrical conduit is NOT the same as PVC plumbing pipe. They may be made of the same basic material but they are not the same product.

In terms of thickness, metallic conduit will be much thinner (OD much closer to ID). There are two types: Intermediate Metallic Conduit which is almost like steel plumbing pipe and is connected with threaded ends, and Electrical Metallic Tubing which is very thin walled and uses special set-screw or compression fittings.

If you want to run conduit though an existing stud wall you'll want to plan ahead to keep the runs as vertical as possible - going horizontal through the studs may prove to be... impractical. :D I'd look around for flexible electrical conduit, which might be more expensive and harder to pull wire through, and will be larger in diameter, but at last you might actually get it into a wall without notching every single stud.
=Smidge=
 
My City's General Plan has a requirement for new commercial charging, but not residential. The local Planning dept. (where I used to work) does not do a great job of following through on this requirement, and needs to get it put into their next Development Code amendment. They said if I provide the language (I used to do their code amendments, so I know what they're looking for), they'll include it in their bi-annual code update. I'll also mention that the residential requirement should be thrown in too. Some cities may vary on how/where they want the language to land. For example, it might be easier to include broad language in the development/planning code vs. the building code (which would be very specific).
 
cinmar said:
My City's General Plan has a requirement for new commercial charging, but not residential. The local Planning dept. (where I used to work) does not do a great job of following through on this requirement, and needs to get it put into their next Development Code amendment. They said if I provide the language (I used to do their code amendments, so I know what they're looking for), they'll include it in their bi-annual code update. I'll also mention that the residential requirement should be thrown in too. Some cities may vary on how/where they want the language to land. For example, it might be easier to include broad language in the development/planning code vs. the building code (which would be very specific).

Yes! I agree. If you come up with a draft of the language could you send it to me in a PM? Thank You!
 
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