Advice on installing a new 220 circuit for EV car charger

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Old 12-22-17, 08:41 AM
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Advice on installing a new 220 circuit for EV car charger

Hi everyone,

I recently bought an electric car. I have been charging with the standard charger, but would like to upgrade. I am looking for advice in planning an installation. Thanks for any help you can provide.

2014 Nissan Leaf with a maximum charge rate of 7kw
Located in Connecticut. House is 20 years old.
Siemens VersiCharge 30 amp EVSE charger. There is an adjustment that can be made on the charger to slow the amp rate if necessary.https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I have an existing 30 amp dryer outlet in my laundry room in a wall that is shared by the garage. I thought I could extend that circuit to the other side of the wall and install a switch so it only used by either the dryer or the charger at one time, but I have read elsewhere that this might be against code?

If that is against code, I will run a new ciruit. My breaker panel is on the exact opposite corner of the house from where I would like to install the unit. So, it is a 60 foot wire run just to get to the garage. Since I have to go up and around a door in the back of the garage, it is probably another 30 feet for the wire to go from there to the mounting spot.

This is what I think I would need to use:
40 amp breaker
90 ft of 8-2 wire? (because of the long run, should I use 6-2?) What kind of wire exactly?
NEMA 6-50 plug

My garage is drywalled and painted. Should I cut the drywall and run in the wall, or use conduit? What type/size conduit is required for a garage? Is there a certain height off the floor it should be run?
 
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Old 12-22-17, 09:57 AM
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First of all, you do not have 220 volts, you have 240 volts. 240/120 volts has been the standard for at least the last fifty years.

Conduit surface run on the finished wall would be easier than tearing up the walls, drilling the studs and then patching the walls. It could be PVC (grey plastic) conduit and look just fine in my opinion. PVC is also much easier to work with than is EMT (lightweight steel) conduit. If you use conduit I strongly suggest that you use individual conductors and not a cable (factory assembly of more than one conductor with an overall sheath) While cable inside conduit IS acceptable it is much harder to pull the cable through the conduit than the individual conductors.

If you take the trouble to find a transfer switch capable of switching the 30 ampere supply between two loads (the charger sand the dryer) you will find it is far less expensive to just run the second circuit for the charger and leave the dryer circuit alone. Plus you get to size the charger circuit to the maximum allowed for the charger. If you think you will ever get a second electric car, or want to install an even larger charger, you can allow for that when you install the new circuit.

Generally speaking, for runs of less than100 feet you do not need to allow for "voltage drop" BUT the instructions for the particular charger may have recommendations for minimum wire sizes for approximate distances and these should always take precedence of general instructions.

If it were me, I would run one inch PVC conduit from the circuit breaker panel to the location where you want to mount the charger. You MAY be required to install a local disconnect switch unless the charger is plug-and-cord connected, which you stated it was. Number 8 copper type THHN/THWN conductors, two "hot" and a number 10 green-colored equipment ground will be needed UNLESS the charger states it requires a 240/120 circuit. If the latter then another wire, this one white, must be installed as well. The two hot wires may be of the same color or different colors but must NOT be white, grey or green. If you think you might want to upgrade in the future then you should consider using heavier wire now rather than having to re-do it in the future.

Note well, the penetration of the fire-rated wall between the garage and the living areas of the house must retain the fire rating. This is done by sealing the penetration with a special fire-rated caulk. You may need to use a steel conduit nipple of specific length where penetrating this wall.
 
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Old 12-22-17, 10:04 AM
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I have an existing 30 amp dryer outlet in my laundry room in a wall that is shared by the garage. I thought I could extend that circuit to the other side of the wall and install a switch so it only used by either the dryer or the charger at one time, but I have read elsewhere that this might be against code?
Yes this is against the code because the dryer calls for "dedicated" outlet. It is probably ok to unplug dryer and plug charger, but cannot have 2 outlets on same circuit.

NEMA 6-50 is 240V 50A outlet. Amazon description says "NEMA 6-50 plug for use with common dryer outlet," but this is not true. NEMA 6-50 is 240V only and 50A, whereas dryer outlets (NEMA 10-30 for older 3 prong, NEMA 14-30 for new 4 prong) supplies both 120V and 240V and 30A. It it possible they just meant it includes an adapter to convert.

You can run 8-2 copper NM or 6-6-8 or 6-6-6 aluminum SER cable.
Aluminum is probably cheaper, but you have to make sure outlet you use is rated for Al. It will have Al/Cu marking.

Is your house single story house? How are you going to run wire from the panel to the garage?
Unless your house is single story house, you will have to cut a lot of drywall. You could run the wire along outside wall if you don't some visible conduit or SER cable. You can run SER cable outside without conduit. You CANNOT run NM outside wall even if it is in a conduit. You will have to run two 8 AWG THWN and one 10 AWG THWN for ground in a conduit. You may paint conduit same color as your exterior wall color to make it less visible.

My garage is drywalled and painted. Should I cut the drywall and run in the wall, or use conduit?
Exterior walls are load bearing walls and therefore you cannot run that large of cable in the wall. If you meant vertical run from the attic, yes you can run in the wall and will look cleaner.
 
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Old 12-22-17, 10:52 AM
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Thank you both for your very helpful replies. Let me provide some more information. The house is a two story house with a full basement. Half of the basement is finished, the half with the breaker box is unfinished. I can get wire behind the finished wall in the basement that I would run by.

I was not thinking that I would have to run any conduit in the basement area, just in the garage. Does this make sense? Based on your answers, I guess I will run conduit in the garage rather than in the walls. If the conduit is only needed in the garage, how does that affect the choice between NM and individual wires? Thanks again for the help.
 
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Old 12-22-17, 11:03 AM
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If the conduit is only needed in the garage, how does that affect the choice between NM and individual wires?
You can run NM without conduit, then just sleeve it in the garage. Depending on how the joist is run, it may not be too hard to run the cable in the ceiling. If joists run parallel to how you run the wire, just have to cut few spots. (2 if lucky)

In some area, running NM along the corner of garage ceiling may be acceptable since it is unlikely the cable will be damaged.

Individual wires must be inside the conduit all the way from the panel to the outlet.
 
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Old 12-22-17, 11:03 AM
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You can run type NM to a junction box and transition to the individual conductors. You CAN run type NM through conduit, it is just more difficult than individual conductors. In the latter case the conduit is only to protect the cable.
 
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Old 12-22-17, 12:12 PM
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Thanks again. I did some checking on wire prices, keeping in mind the idea of futureproofing for cars and chargers in the future that can handle higher charging rates. I found that a 125 ft roll of 6-2 romex is about $165, vs, $115 for 8-2. If I am going through the work, I would think I would want to install a 50 amp breaker and the 6-2? Does this make sense? Is this the right type of wire? Would this fit in 1" PVC in the garage?

Can I run the continuous wire right out of the wall and through a box into the PVC, or does there have to be a cut and connection at the box?

Is this the right type of wire?
https://www.homedepot.com/b/Electric...z0rqhcZ1z10myq
 
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Old 12-22-17, 02:37 PM
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Yes you can use 6-2 NM

Can I run the continuous wire right out of the wall and through a box into the PVC, or does there have to be a cut and connection at the box?
You don't even need a box except for the box where you will mount a outlet. You can just pull NM, then sleeve the cable straight into the PVC conduit. No need to cut wire.

Pulling 6-2 in a 1" conduit is possible, but may be challenging especially if there are any bends. You may want to increase conduit to 1 1/4 to make it easier.
 
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Old 12-22-17, 07:47 PM
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Exterior walls are load bearing walls and therefore you cannot run that large of cable in the wall.
This is not exactly true. The holes would have to be VERY large to weaken the studs of a load bearing wall. Most cases you can drill a hole 1/3 the width of the stud. Of course, local authority having the last word on things like that.
 
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Old 12-22-17, 09:09 PM
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Well. Technically you can run it through the bearing wall studs, but running it along full length of the wall, I would not recommend for wire of that size. That weakens the wall too much in my opinion.

Drilling holes for 6-2 NM would require 1". Leaving only 1 1/4" on each side assuming the hole was drilled at perfect center. Also in many case holes will be drilled in angle because the drill does not fit in some stud spacing. 3/4" may be workable, but not easy and greater chance of damaging sheathing. Even with 1" hole, it will not be easy to pull it through every studs. The easiest way would be notching.
 
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Old 12-23-17, 07:35 AM
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Thanks, I will run the PVC. Makes more sense. Wouldn't it be easier to snake the wire before PVC is connected? Does it matter if I have a 50 amp breaker using a 30 amp EVSE?
 
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Old 12-23-17, 10:16 AM
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Does it matter if I have a 50 amp breaker using a 30 amp EVSE?

Yes, it matters. If you are feeding a 30 amp receptacle you should use a 30 amp breaker. I would probably use 6-3 NM-B cable and feed a small subpanel and feed it with a 60 amp breaker. Then, feed the receptacle with a 30 amp breaker. This also gives you future 120 volt circuit capability too.
 
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Old 12-23-17, 02:15 PM
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Wouldn't it be easier to snake the wire before PVC is connected?
Yes. It will be easier.

Does it matter if I have a 50 amp breaker using a 30 amp EVSE?
Your charger does have 6-50 plug. So, 50A breaker is fine as long as you have 50A outlet at the end.

I am not sure if your charger actually puts 30A load, but if it does, 30A breaker may trip after charging for a while. You are not supposed to put load larger than 80% of circuit rating in the first place. So, the maximum load on 30A circuit is 24A.

As CasualJoe suggested, pulling 6-3 and installing a sub panel is not a bad idea. Will cost bit more, but more flexible later.
If you are not ready to install sub panel yet, just pull 6-3 and cap neutral (white wire). You can install a sub-panel when you need later.
 
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Old 12-23-17, 05:14 PM
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By code in a closed conduit system the conduit must be fully assemble before pulling. You can add a string as you assemble.
 
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Old 12-23-17, 10:00 PM
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Thank you to all for their help. I'm going to summarize what my current plan is.

install a 40 amp breaker in my box in an open slot. (see attached pic)

Run 6-2 Romex from the box, and behind the finished wall in the basement (behind copper pipe in picture.)

When I reach garage, run in 1 1/4" PVC up and over door (see picture) and across to NEMA 6-50 Outlet in box.

Does anyone see any problems with any of this? Thanks.
 
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Old 12-23-17, 10:45 PM
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I would run 6-3 instead of xx-2 cable in case you need a neutral or decide to install the subpanel..
 

Last edited by pcboss; 12-30-17 at 12:29 PM.
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Old 12-24-17, 11:15 PM
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It looks like it's over $100 (70%) more for the 6-3 wire vs. 6-2. Is it possible future electric car chargers would require the 6-3?
 
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Old 12-25-17, 02:43 AM
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Ream The ends of the conduit and add a bushing to protect the cables.

​​​​IIRC some chargers need the neutral . Hard to tell as they are still evolving.

 
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Old 12-26-17, 12:24 PM
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So, if I go with 6-3, is this the right wire? Is the quality good? https://www.amazon.com/Southwire-639500 ... s=6-3+wire
 
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Old 12-26-17, 12:28 PM
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Southside is a good brand. You may get better pricing locally from a supply house.
 
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Old 12-30-17, 11:52 AM
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Thanks for the suggestion of looking locally. My local supply house has the wire a litte bit cheaper and can provide good advice. I am also glad to support local businesses.
 
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Old 12-31-17, 01:38 PM
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What size PVC for the 6-3 wire?
 
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Old 12-31-17, 02:15 PM
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Individual conductors are much easier to pull in then a cable. But if you really, really want to use cable, I would use 1 1/2" or 2". The cable will be in a wet location so you will need to use UF or some other cable that is approved for a wet location.
 
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Old 12-31-17, 02:19 PM
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Thanks, the conduit is just for the wire run on the surface of the wall in an attached garage, about 30 feet. No chance of wetness.
 

Last edited by jake14mw; 12-31-17 at 02:22 PM. Reason: clarity
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Old 12-31-17, 02:29 PM
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If that is all you are running you might be OK with 1 1/4" pipe then.
 
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Old 01-01-18, 05:49 AM
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Thank you very much for your help.
 
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Old 01-02-18, 10:28 AM
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Shifting gears a little, I have thought about the fact that I might get another electric car in the future, and am trying to plan for maybe charging two cars at once. I'm not trying to go crazy and install 2 240 circuits, but I am wondering if it would be smart to run another new 110 line into the garage while I am doing the new 240. Currently, I am charging my 2014 Leaf SL by plugging into an outlet in the ceiling in my garage used by a garage door opener. It is the only outlet that can reach out into the driveway. This circuit is shared by the garage door openers and three other outlets. So, I was thinking to run another 20 amp 110 circuit, so that the outlet would be more convenient to the driveway, and dedicated.

Does this cause any code issues running these wires together? Does 20 amp with 12-2 wire make sense? The existing plan for the 240v circuit is to run 6-3 wire for that. Thanks.
 
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Old 01-02-18, 08:44 PM
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I don't see why any 240V charger needs a neutral, or will ever, especially with the tens of thousands of these being installed right now without one. I'm installing lots of these without one, but if you want the extra expense for possible future "who knows," it's your choice.

Yes, you can run multiple circuits together in the same conduit.

To clarify terminology, "wire" is what we call a single conductor, "cable" is the NM (Romex) we are talking about here, containing multiple wires.

We've got you saying 240 instead of 220, now if we could just get you to say 120 instead of 110!
 
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Old 01-03-18, 12:27 AM
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Thanks, I'm just following the advice here and elsewhere of people that said that the 6-3 might help in the future, but I know what you mean. As far as installing the two outlets from the two different "cables" on the wall, codewise or logically, is there a certain distance apart that the two boxes should be, or need to be?
 
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Old 01-03-18, 08:43 AM
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Make them far enough apart that something mounted to one isn't in the way of the other, but they can be mounted side-by-side, if you want.
 
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Old 01-06-18, 07:51 AM
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So, I went and purchased the materials yesterday at my local electrical supply house. I decided to only run the 6-3 cable. I ran into one problem. When he laid everything out on the counter, there was a standard metal box for the outlet, and 1 1/4 inch PVC to come down to it. So, I asked the guy, how do I connect the PVC to the metal box? The cutouts were not nearly big enough in the box. He looked at it with a puzzled look. He seemed unsure of how it could be done. So, I just left with what I had, and figured I could ask the question here. Thanks.
 
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Old 01-06-18, 08:35 AM
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For 1 1/4" PVC you will likely need a larger box. A 8x8x4" pull box will work for you. Off that pull box you could then use a 3/4" or 1" standard or offset nipple to go to the device box. A deep 4x4x2 1/8" box with an industrial cover will likely work. You will need to make your own holes.

Note: I think I have seen 4x4 boxes at big orange with 1" KO's.
 
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Old 01-10-18, 09:22 AM
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A "standard metal box?" There is no such thing except that it will be different to each specialist. You're getting a conduit bigger than necessary because you want to pull a cable with an extra wire you don't need. That's all fine, but now you have even more work to make it all fit.

Yes, you can get a 4" square steel box with 1" KOs at places like Home Depot.

If you go to a real supplier, you can get the 4-11/16" box with 1-1/4" KOs: https://www.garvinindustries.com/ele...saAvwzEALw_wcB

It's possible you can get one at the DIY stores, but HD's website is impossible for a pro to navigate. Their data entry people know nothing about the product and list them with no consistency so you can't search for them effectively. I gave up.
 
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