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Running conduit

Discussion in 'Model S: Battery & Charging' started by markb1, Jan 9, 2013.

  1. markb1

    markb1 Active Member

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    I want to run a conduit to my electrical panel. It's going to run laterally along the wall of my garage, but then it needs to enter the wall and turn downward to connect to the top of my electrical panel. The panel is on the outside of the garage, recessed into the wall, and the conduit will be on the inside of the garage, on the same wall, so the conduit will have to penetrate the wall. I was planning to use PVC conduit.

    What is the best way to make the turn into the wall? If I use a 90-degree conduit elbow, it will extend out from the wall a ways, due to the gentle turn. I want to make a much sharper turn to keep the conduit close to the wall. Is there some sort of pull box that I could use for this purpose that would be partially recessed? This seems like the sort of situation that electricians would run into from time to time, but I haven't found anything googling.

    Thanks.
     
  2. dtich

    dtich #P708

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    #2 dtich, Jan 9, 2013
    Last edited: Jan 9, 2013
    yep, there's L's and pull elbows like:

    3/4 in. Pull Elbow-R5240102 at The Home Depot

    3/4 in. Service Entrance Elbow-59507 at The Home Depot

    not sure if they make service entrance L's in pvc, but think so...

    edit: yeah, here, pretty ugly tho, :)

    3/4 in. Non-Metallic Type LB Conduit Body-E986E-CTN at The Home Depot
     
  3. swegman

    swegman Member

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    Is PVC acceptable, or should it be a metal conduit? I want to install coduit also. My panel box is in the basement that is on the opposite side of one wall of the garage. I would like to have the conduit penetrate the wall and run close to the floor, then run up the wall where one garage door is loacted to cross the wall over the top of the garage door and then run down the wall on the opposite side of the garage wall. The receptacle (or HWPC) would be installed on the pillasr wall between two garage doors. Total length is 56 feet. Also, what size conduit should I install so an electrican can later install either a line for a 14-50 or a line for the HWPC? Thanks.
     
  4. markb1

    markb1 Active Member

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    I'm familiar with those, but they don't do what I want. Those are good when the turn is outside the wall, but I really need to make a turn inside the wall, too, so the conduit can enter the top of my panel.
     
  5. mitch672

    mitch672 Active Member

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    You should be able to locate some 15 degree offsets, and stack them back to back, that should net you a small offset to be able to enter the panel. You will likely need to use 1" or 1 1/4" pipe, it depends on the number of conductors and their size.
    Google "conduit fill calculator" and you will find some.
     
  6. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    PVC is acceptable.

    Can you work in the wall? You could use 2 LB's back-to-back with a very short coupling -- one in the wall just above the panel and another facing it that turns the wiring the direction you wish to go externally. I'll tell you, though, it's going to be very tough to work with, especially if you're using AWG 3 wires for the 100A HPWC install. It's a hard pull to make 2 turns in such a short span, but if it's all you have to work with, good luck. :)

    By NEC standards you're not supposed to do this, but you might be able to assemble the wiring into the first LB that goes into the panel, then install the LB, then work the rest of the conduit.

    Because you're using conductors larger than AWG 6, you must use insulated fittings. If you're using PVC, you have nothing to worry about because you will have them.

    The LB inside the wall must be capped.

    You'll need 1" conduit for 3 conductors of 3 AWG (a 240-volt only install) for HPWC. Reference: NEC table C10 for sch 40 PVC.
     
  7. markb1

    markb1 Active Member

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    I'm going to assume some of that was addressing my question. :) (Looks like you answered my question and swegman's questions as if we were the same poster.)

    Yep. I've already removed the drywall above the panel.

    Thought about that. In my case, I'm just installing a NEMA 14-50, but I want to have some extra capacity in there to run other circuits in the future without busting open the wall again.

    Capped? Meaning the access plate needs to be installed, or something else?

    Another possibility is maybe I could create my own offset by making two gentle bends in a piece if conduit. That will require a weird oblong whole in the drywall.
     
  8. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    Yes. I've seen some DIY jobs where the plate was missing because after installation they couldn't install the screws.

    If you have a heat gun, you can tease yourself the right shape, but you have to be careful not to collapse the conduit. Good luck.
     
  9. swegman

    swegman Member

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    FlasherZ, what size conduit would you recommend so an electrican can later run a line for a 14-50 outlet and a second line for the HPWC Two lines in the conduit). I assume the 14-50 requires 6 gauge wire, and page 4 of the installation manual for the HWPC says to run 3 gauge wire for L1 and L2 and 4 gauge wire for GND (why is GND a thinner wire?). My run from the panel box will be about 56 feet.
     
  10. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    I would recommend a subpanel instead of two circuits. Put a 1 1/4" conduit in place, pull 3 AWG #2 conductors plus a #4 ground and place a 125 amp subpanel (a simple 4-pole panel) above your HPWC. From that subpanel run two circuits - a 50A 14-50 on #6 (with #8 ground) and a 100A to the HPWC on #3 (or #2 -- honestly, I just don't use #3 because #2 is easier to find and more common) with a #6 or #4 ground.

    The equipment grounding conductor (a/k/a safety ground) isn't intended to carry current on a continuous basis -- it's simply there to create enough of a current path so that breakers will trip in case of a fault. That's why it's permitted to be smaller.
     
  11. mulder1231

    mulder1231 Active Member

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    Coincidently, I had this type of work done in my garage just this morning. Two 90 degree metal conduit elbows go from the wall to the box that houses the panel. One is 2" diameter and the other 1 1/4". Here's a pic, the plaster for drywall repair is still wet and needs to be sanded, painted. Once it's all done it will look just fine.

    image.jpg
     
  12. swegman

    swegman Member

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    FlasherZ, curious as to why you suggest the installation of a sub-panel. I have 800 Amp service to the house, with four 200 Amp panel boxes located on the other side of one wall of the garage. The 14-50 line would be about a 30 foot run for a possible second future EV. The HWPC line would be about a 56 foot run (because the line would have to go up the side, over and then down one garage door to get to the second car bay) for the model S. The garage currently has three 120 volt 20 Amp outlets (almost never used). Installing two double circuit breakers in the panel boxes are no problem. I would like to keep the garage as uncluttered as possible. So why do you think a sub-panel is the best way to go? I'm interested in your opinion. Thanks
     
  13. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    A few reasons...

    First, wire is expensive and so using a single run of #2 to a place keeps you from having a long run of #6 in addition to the HPWC run. Now, you might ask yourself whether separate long runs of #3 and #6 are going to be about the same cost as #2... therein lies the second reason:

    Any time you run more than 3 current-carrying conductors in a raceway, you must de-rate the wire capacity. Carrying 4-6 conductors in a single conduit requires that you de-rate the wire to 80% of its ampacity (NEC 310.15(B)(3)(a)). As #3 THHN is rated at 115 amps (90 degC), de-rating it makes it only good for 92A, and so it cannot be used for the HPWC. De-rating #6 makes it good for 60A, so it's still ok. As a result, if you wanted to run these two circuits in the same conduit, you have to use #2 anyway for the HPWC. So by placing a subpanel, you make only a single #2 run, then branch from there.

    Finally, NEC EVSE code (625.23) says that when > 150v are used for supply equipment, a "disconnecting means shall be provided and installed in a readily accessible location". In the case of the UMC, the plug is ok. In the case of the HPWC, the breaker counts. Some jurisdictions judge this differently -- for some, the breaker in the panel elsewhere in the building works fine; for other jurisdiction, "accessible" can mean that it must be in the same garage, etc. A subpanel provides this.

    A small subpanel with less than 6 breakers does not require a main. I use a small GE load center for this - the TL412CP.

    Here's a photo of my install:
    CameraZOOM-20130110110020611.jpg

    The right conduit comes from my panel. The left conduit goes to my 14-50 between doors #1 and #2. When my HPWC arrives, it will be installed directly below.
     
  14. swegman

    swegman Member

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    Thanks for the info. Makes sense. I'll check with an electrican for a subpanel from Square D equivqlent to your GE panel. My house was built with Square D panels and I would prefer keeping consistency, unless you tell me there is a problem with Square D.
     
  15. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    Not at all. I rather like Square D, especially the QO series (HOM are good too). I like the GE panel's compactness, and my home was built with CH & GE panels.
     
  16. swegman

    swegman Member

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    Square D QO is what the house was built with. Just looked at home depot's website. They carry a panel but it uses HOM breakers. Rather stay with QO. Electrician should be able to find the right box. I just plan to run the conduit and let him install the lines. Thanks.

    Is there anything special I should tell him. Any specific wire or something you are partial to?
     
  17. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    Not really, it's a basic THHN (if everything's inside) or THWN (if there are outside portions) wire.

    The Square D QO part number would be QO148L125GF for the equivalent to mine.
     

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