What to do with wires when installing light switches/plugs

Discussion in 'Electrical Forum discussion & Blog' started by amateurplumber1, Sep 9, 2013.

  1. amateurplumber1

    amateurplumber1 Member

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    This seems pretty silly, but I've installed a few new light switches recently, and I am curious about how the right way to do it is. I've always been told (and read when researching) that you shouldn't install the switches straight into the holes in the back (which our houses builders did, lol). But what Im curious about is putting the wire under the screw. I've come across two kinds of set ups: one with a plate that is immovable in upward direction and a screw that comes up so you can loop the wire around it, and one that is almost exactly the same but the plate moves up.

    My question is about the second kind (plate moves up and screw moves up, so there is a space under the plate and screw). Do I loops the wire around the screw and OVER the plate, or loop the wire around the screw UNDER the plate? I've done it under the plate when I've ran into this type of switch/plug and all of the switches/plugs have worked fine. It is kind of a pain to get it under there, though.

    However, I'm pretty sure that the plate comes up so you can just jam the wire in there and just screw the screw down. The reason I think this is because for the kind of screw/plug where the plate does NOT move, you can jam the wire in the holes in the back and the plate pushes down on it when you screw the screw down. But I dont know, because in the type with the movable plate the plate doesnt do anything if you put the wire in the holes in the back (those are held in via a spring mechanism or something similar).

    Hope this made sense lol. Thanks guys!
    Last edited: Sep 9, 2013
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    The stab-loc on a switch or receptacle is UL approved as a method to terminate #14 conductors.

    If the plate has a plate for the placement of the conductor then stripping the conductor and sticking it straight in is the method approved for this device.

    Somewhere someone came up with the idea that wrapping the conductor around the screw in some way makes for a better installation but it is nothing more than a wives tale.

    UL test each device with the conductors terminated in their listed manner at the rated ampacity for a period of three hours. This is done several times for a predetermined amount of time before it passes the UL test.

    If I had penny for every time someone posts on a discussion forum that the approved method is not to par then I would have my very own airline, but, alas, after being in business for half a century I have yet to find so many failed installations. This must be something special to their area. If it is special to “their” area wonder what this is saying about electricians that must have been the ones that taught them.
  3. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA
    We have had this argument and I have tried to help you buy that airliine.

    I don't like to use stablocs on receptacles because people plug stuff in and jerk plugs out of them on a regular basis.

    It is my theory, not backed by any testing done by UL, that a sturdy receptacle that retails for $1.20 is going to last plenty longer than one that retails for $0.20.

    A fraction of my business is maintenance in apartments, and I have seen many failures of stabloc receptacles that have been installed for three or four decades.

    Often the common in a three wire circuit that is joined using the two stabloks on one outlet. That makes for a fine mess.

    I don't see similar issues with switches or the stab connections commonly found in recessed lights, but those are not subjected to the physical abuse that the outlets are.

    Go ahead and back stab outlets if you care to. Me? I can find the time to bend a loop in a piece of wire and tighten it under a screw.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,631
    Location:
    Cave Creek, Arizona
    There is another type of connection, where the wires are inserted in the holes in the back, BUT you have to tighten the screws to clamp the wires between the contact surfaces.
  5. bluebinky

    bluebinky Member

    Messages:
    393
    Location:
    Santa Clara, CA
    Yuck -- my casual reading of the NEC says "don't do that...even under screws".
  6. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    No problems on switches or other type of stab-loc should say something in and of itself.

    The problem is not the method being used but the load imposed on the receptacle. Wrapping the wire around the screw in no way keeps the receptacle from failing, all it does is takes the point of fail from one place to another.
    Ever plugged in a cord only to have it fall out? The failure has happened in the tension of the receptacle. It still has failed.

    When doing maintenance work in apartments do you use a tension tester on devices? Bet if you were doing maintenance in a hospital you would learn how to do tension test on receptacles.

    Finding time to wrap the wire around the screw is good except it takes time and when bidding apartments time (labor) is your most expensive cost. How do I know this? Apartments were the only source of my income for a period of about eight years. I was doing roughly 2000 units a year. Yes all were back stabbed and for the life of me I just can’t see all this failure that I hear about. You see I had the maintenance contract on these units for the same time period and yet have one failure due to the stab-loc to find.

    To those who preach how bad stab-loc is I try to point out what the NEC has to say about receptacles that can be found in Table 210.21(B)(2)
    If the total load on a 15 amp receptacle is 12 amps then no matter the method used to terminate the conductor changes this. Even if this 15 amp receptacle is installed over a kitchen countertop or if it is the one at the bathroom sink the total plugged in load can only be 12 amps. Anything more will cause the device to fail. Now what is the size of the over current device on these circuits? Oh, that is right it is a 20 amp device that can only be loaded to 12 amps at the receptacle because the receptacle is the weakest link. Now while wrapping the wire around the screw on kitchen and bathroom receptacles are we using 20 amp devices? No, then what are we gaining?

    Now for the record just how many of those receptacles in the apartment failed the tension test?


    Google receptacle tension tester
  7. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    Do switches and receptacles still employ the undercut "binding head" screws?
  8. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA
    Indeed so, under more recent codes.

    30 years ago? Not so much. That may be how long a stabloc takes to deteriorate, but deteriorate it does.
  9. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA
    A good argument for using the slightly better quality outlets. I never put in a $.20 outlet. I try to get my customers to go for the really tough units that have the strap pass entirely behind the outlet, and have screws and plates on the side. They cost on the order of $3. I suppose it is less painful for the apartment owner when he is faced with buying five of them as opposed to hundreds or a thousand.


    I haven't the foggiest notion. I'd say a quite a few. Seeing as I don't install "contractor grade" crap, I am not overly worried about the question. But I will look up the tool, thanks.
    Last edited: Sep 13, 2013
  10. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Hospital grade is the top of the line when it comes to receptacles but NFPA 99 says that the receptacles must be tested for tension every once in a while. Wonder why they want the best of the best tested for tension?

    When all someone does is service work they can afford to spend an extra dollar on a device as most of the time they are charging for time and material but when you are entering a bid on new installation you are in competition with others then you do the job as cheap as possible.
  11. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,126
    Location:
    Houston, TX

    Because they want to make sure the morphine pump is working when they kill you ?

    No room for error.

    As far as I know all of the connection on a outlet can be used, if used properly.


    Hospital grade just means it has stainless parts.
  12. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA
    I completely understand the second point.

    And I assume that hospitals need test their receptacles for tension because they can't have plugs falling out and because nothing man made lasts in perpetuity.
  13. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Let me start this post by saying that if I have sounded rude at any point in this thread it was not my intention. It was pointed out to me that some of my post could have been taken as rude but after some discussion with a group it was determined that I was only trying to make a point although a couple of the fine folks in the discussion said I sounded rude.

    If anyone has taken anything posted by me as being rude I apologize.

    The reason they test receptacles in hospitals is for receptacle failure. The failure occurs at the blades instead of the termination points.

    The moral of this exercise is, receptacles that are overloaded will fail. Even the best products on the market will fail if not used in the manner for which they were designed.
  14. DonL

    DonL Jack of all trades Master of one

    Messages:
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    Location:
    Houston, TX


    I did not think you were being rude, I thought you were speaking the truth.

    Sometimes the truth hurts.
  15. bluebinky

    bluebinky Member

    Messages:
    393
    Location:
    Santa Clara, CA
    You may seem so to a first-time poster. I for one enjoy your posts.
  16. Hammerlane

    Hammerlane New Member

    Messages:
    252
    Location:
    Ohio
    Push in connector not good?

    Attached Files:

    Last edited: Sep 16, 2013
  17. Hammerlane

    Hammerlane New Member

    Messages:
    252
    Location:
    Ohio
    SCrew and Clamp is better

    Attached Files:

  18. Hammerlane

    Hammerlane New Member

    Messages:
    252
    Location:
    Ohio
    Side wired is best?

    Attached Files:

  19. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    That is exactly how I wired an outdoor cut-off switch for a pump, only I was using #12 stranded THHN, which was a pain to get secured beneath the screw heads, which is why I was wondering about binding-head screws.
  20. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    After stripping off the insulation take another 1/4 inch bite of the insulation but leave it at the very end of the conductor and guess what, yea it goes under the screw easily.
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