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Can I install a NEMA 14-50 in my existing circuit panel? (Pics included)

Discussion in 'Model S: Battery & Charging' started by DingDingDao, Jan 31, 2014.

  1. DingDingDao

    DingDingDao Member

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    #1 DingDingDao, Jan 31, 2014
    Last edited: Feb 18, 2014
    I'm trying to figure out if I can install a NEMA 14-50 using my existing circuit panel, but I honestly have no idea what I'm looking at. I'm hoping some of the electrical gurus on the forum can give me some insight. Pics of the breakers and panel sheet are below.
    YPpo6EB.jpg
    GWw4I7l.jpg

    Note that on the right side of the breakers the labels are off by one position, because my landscaper moved all the breakers down one position to add a new breaker for the bbq. Anyways, all comments/suggestions are appreciated. Thanks all.

    UPDATE (2/18/2014) - I had an electrician in this morning to install the NEMA 14-50. Smooth install, only took him an hour and a half and a very short 2 foot run (the outlet is on the inside of the wall directly opposite the circuit breaker panel). He looked at the breakers on the right side and you guys were right--my landscaper's wires were too short to make it to the bottom of the panel, so he installed the breaker for the BBQ in position 3 and moved all the other breakers down one position. Poor planning on his part but no harm done. The electrician relabeled everything and I'm all set to go when I take delivery at the end of March.
     
  2. markb1

    markb1 Active Member

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    It looks like there's room on the panel. It will take up the two slots on the top right. (You need two adjacent slots.) BTW, looks like the exact same panel as mine.

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    I don't understand why your landscaper had to move any breakers, though. You probably shouldn't let landscapers do electrical work.
     
  3. DingDingDao

    DingDingDao Member

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    Haha, nice. Did you install a NEMA 14-50 or the HPWC?
     
  4. markb1

    markb1 Active Member

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    14-50.

    It would be nice to see what's behind the cover. That might shed some light on why they moved the breakers. Here's a picture of my panel with the cover off (pre 14-50 installation):

    100_0228.JPG
     
  5. N4HHE

    N4HHE Member

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    Agree, makes little sense that your existing breakers were moved down. Could have knocked out one of the two blanks at the top for the BBQ and that would have left two at the bottom for your Tesla.

    You have some interesting breakers that I'm not familiar with. Have seen the dual 120V breakers before but slots 3 + 5 and 7 + 9 appear to have a 120, 240, and another 120. Neat. I understand how that works too. You just don't seem to have the conventional two slot 240 breaker. No reason you can't its just that you don't.

    240 volts requires two adjacent slots. Your incoming power consists of L1, L2, and Neutral. The box's backplane is wired with L1 and L2 alternating every slot. You need L1 and L2 for 240 so you need two slots. For 120 you only need L1 or L2 (and Neutral) so those only need one slot.

    Looks to me you have a Square D Homeline distribution panel. I have a 25 year old Square D QO which is too old to support the dual 120 breakers. Bought one and tried it anyway, didn't work. I used a Homeline in the detached garage.
     
  6. zwede

    zwede 2013 P85+

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    You also have 200 Amp service, so you are all good. You don't have to worry about charging the car at the same time the house AC is on and you have cookies in the oven. 200A will feed all of it.
     
  7. FlasherZ

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

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    Sometimes it feels better to make a job harder. :) No idea, either, this panel has no breaker restrictions (unless he was leaving that space because he was used to split-buss panels).

    Those are HOMT quad breakers; they allow for tandem breaker use in conjunction with a 240V circuit. Incredibly useful breakers, but only work in some panels. You have to make sure the panel accepts them -- this one does.

    Nothing wrong with the Homeline, they're basically the same as any other 1 inch breaker out there - Bryant BR / Siemens Q / Murray MP / etc. I prefer QO but they are a bit pricier, also a big fan of Cutler-Hammer CH series. As for trying to make it fit anyway, never try forcing a breaker - many times they can be forced onto a buss but the results are usually not good.

    As far as load calc, you look good based on a 200A service. 50A is pretty beefy for an A/C unit, is that a heat-pump?
     
  8. N4HHE

    N4HHE Member

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    The QO manual said slots that support tandem (I couldn't remember that word earlier) breakers will be marked. Mine wasn't marked. And the tandem QO didn't fit. The non-electrical lip was different on tandem and didn't mate with my panel. Still don't understand why. Could have modified the panel but didn't want to cut/grind/file on a live box. In the end I had enough room without having to convert singles to tandem.
     
  9. DingDingDao

    DingDingDao Member

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    To be honest with you, have no idea. It's a new construction and my first home. Are heat pumps common in Southern California? We don't need heat in the house very often...
     
  10. AlMc

    AlMc 'Senior Moments' member

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    Regardless of whether it is or is not a heat pump the answer to your original question is 'yes'.
     
  11. yobigd20

    yobigd20 Well-Known Member

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    #11 yobigd20, Feb 2, 2014
    Last edited: Feb 2, 2014
    those two dual-pole breakers @ 3+5 and 9+7 are very interesting. I've never seen breakers like that before. It seems somebody made a dual-pole breaker than can hold a 240V circuit as well as two 120V circuits. That is pretty cool. So you definitely have room then. I don't know why your landscaper moved circuits around (was he a certified electrician?). The only reasons I can think of is #1 he cut the wire too short and needed the spot at the top (amateur mistake), or #2 there is something blocking the top two slots and the bottom spot (I have no idea unless you pull the panel off, but I don't recommend doing this unless you know what your doing - can be lethal if you touch the wrong thing). So I am going to go under the assumption that the empty slots are blocked (if they aren't blocked, then your fine as you have two open slots at the top right).

    ASSUMING you can't use those empty slots, you can rearrange the breakers so that you have a single pole DUAL 15A breaker in slot 16 and move the BBQ circuit (slot 15) one over to the left. Then pull out the dual 20A breaker (slot 13) and put in another one of those cool dual pole breakers with a 50A + 20A + 20A configurations which would occupy the now free slot 15 and slot 13. Then you're all set. No need for another subpanel here.

    A quick google search shows that new combination breakers are called 'quadplex circuit breaker'. https://www.platt.com/platt-electric-supply/Circuit-Breakers-Residential-Quadplex-Breakers/Eaton/BQ2502120/product.aspx?zpid=6330

    Note: I am not an electrician. I do not know if the breaker linked above is correct and ok for this install. I am merely pointing out that I think it is possible.
     
  12. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    I thought 50 amps was about normal for an A/C unit and 40 amps was about minimum.
     
  13. yobigd20

    yobigd20 Well-Known Member

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    I'm pretty sure my A/C unit is on a 30 amp 240V breaker.
     
  14. AlMc

    AlMc 'Senior Moments' member

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    Just visually checked mine. 50amp
     
  15. EarlyAdopter

    EarlyAdopter Active Member

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    My A/C (circa 1991) is on a 50A breaker. Maybe newer ones are more efficient and can get by with only 30A?
     
  16. markb1

    markb1 Active Member

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    My house (built in 2010) has a 40A breaker for the A/C. Probably depends on the size of the unit, which will be matched to the house size and the climate.
     
  17. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Nope. Mine is 19 SEER and three years old.
     
  18. AlMc

    AlMc 'Senior Moments' member

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    Bingo!
     
  19. FlasherZ

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

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    Those slots currently covered by the blanks should be able to be used, unless there's a mechanical defect - at least according to the panel's label.

    No need for a subpanel either way, that's a good thing!

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    Correct, it is sized based on the appliance nameplate. 30A/40A are common for compressors in most homes. I've seen 50/60/80/90A for commercial installations, so it's nothing to panic or worry about. It was just a random observation, I'm sure there's a reason for it.
     
  20. N4HHE

    N4HHE Member

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    1500 sq feet, 2004 Carrier 13.3 SEER, 70A circuit.
     

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