Grounding Switches

Discussion in 'Electrical and Wiring' started by dglass4321, Apr 16, 2017.

  1. Apr 16, 2017 #1

    dglass4321

    dglass4321

    dglass4321

    Member

    Joined:
    May 20, 2012
    Messages:
    8
    Likes Received:
    0
    We started a refresh of our 22 year old kitchen. We are having the cabinets refinished, new appliances, LED lighting and new flooring. I'm replacing the old white outlets and switches with black ones to compliment the granite. I'm finding that all the new switches have a ground screw. Why is this necessary? I understand about grounding outlets but why switches? It seems like it is unnecessary since a switch isn't a complete circuit.
     
  2. Apr 16, 2017 #2

    slownsteady

    slownsteady

    slownsteady

    Administrator Staff Member Admin Moderator

    Joined:
    Jun 6, 2009
    Messages:
    6,541
    Likes Received:
    1,174
    Not the classic scientific answer, but since there is current present, there has to be a way to ground it. And AFAIK all components (fixtures, boxes, etc.) need to be grounded throughout the circuit.
     
  3. Apr 16, 2017 #3

    Snoonyb

    Snoonyb

    Snoonyb

    Well-Known Member

    Joined:
    Sep 30, 2006
    Messages:
    2,899
    Likes Received:
    506
    Every switch has a hot lead connected to it.

    Between melamine and plastic boxes, there were metal boxes and there was a ground connection through the metal frame of the switch, the screw to the box, however this only worked if the box was bonded and/or there was a grnd. conductor present.

    So, plastic boxes, wet hands=murphy's law. Code are designed to protect you, from you.
     
  4. Apr 17, 2017 #4

    dglass4321

    dglass4321

    dglass4321

    Member

    Joined:
    May 20, 2012
    Messages:
    8
    Likes Received:
    0
    I can understand all of that but I guess I was unclear on the topic. I neglected to mention that none of the old switches had grounding lugs. I installed them myself 22 years ago when we built the house. And they aren't an odd brand; they are Levitron Decora switches that I bought at Home Depot and they do not have grounding lugs. Obviously during the past 22 years it became a requirement. What is frustrating is that very few of the switch boxes have a ground wire present and the boxes are plastic so what am I supposed to ground to!
     
  5. Apr 17, 2017 #5

    nealtw

    nealtw

    nealtw

    Contractor retired

    Joined:
    Nov 4, 2010
    Messages:
    23,892
    Likes Received:
    3,117
    You could add a short piece of wire but also take note that the box has a piece of steel that runs up one end to connect the ground to the switch when the switch is screwed in place.
     
  6. Apr 17, 2017 #6

    Snoonyb

    Snoonyb

    Snoonyb

    Well-Known Member

    Joined:
    Sep 30, 2006
    Messages:
    2,899
    Likes Received:
    506
    If there is no grnd conductor present, then you just ignore it, because you cannot and are not required to correct the uncorrectable.
     
  7. Apr 17, 2017 #7

    nealtw

    nealtw

    nealtw

    Contractor retired

    Joined:
    Nov 4, 2010
    Messages:
    23,892
    Likes Received:
    3,117
    House 22 years old, has a ground.
     
  8. Apr 17, 2017 #8

    Snoonyb

    Snoonyb

    Snoonyb

    Well-Known Member

    Joined:
    Sep 30, 2006
    Messages:
    2,899
    Likes Received:
    506
    From post #4; "What is frustrating is that very few of the switch boxes have a ground wire present and the boxes are plastic so what am I supposed to ground to!"
     
  9. Apr 17, 2017 #9

    nealtw

    nealtw

    nealtw

    Contractor retired

    Joined:
    Nov 4, 2010
    Messages:
    23,892
    Likes Received:
    3,117
    If the original switches didn't have a ground screw it would be reasonable for some one to wrap the screw in the box and cut the extra wire off. Then the ground strap will do the job.
    If there is no ground there, non of this will matter much.:)
     
  10. Apr 17, 2017 #10

    slownsteady

    slownsteady

    slownsteady

    Administrator Staff Member Admin Moderator

    Joined:
    Jun 6, 2009
    Messages:
    6,541
    Likes Received:
    1,174
    q1: so 22 years ago, you installed plastic boxes?
    q2: is there a bare ground wire in the wire runs (white, black, bare or green)?
     
  11. Apr 18, 2017 #11

    Snoonyb

    Snoonyb

    Snoonyb

    Well-Known Member

    Joined:
    Sep 30, 2006
    Messages:
    2,899
    Likes Received:
    506
    See post #4.
     
  12. Apr 18, 2017 #12

    bud16415

    bud16415

    bud16415

    Fixer Upper Staff Member Admin Moderator

    Joined:
    Feb 5, 2013
    Messages:
    4,654
    Likes Received:
    1,597
    The only metal you come in contact with given a plastic cover plate is the heads of the screws that hold the cover on. They are threaded into the steel frame of the switch. In the unlikely event the power shorted to the frame a safety ground wire connected to the switch would make a path to ground and trip the breaker. If a metal box was used and it was grounded there would be no need for the ground wire as the metal frame is attached to the box.

    If it were mine and I had the safety ground in the cable I would attach it. If I was replacing the switch and it was old work and no ground was there I wouldn’t give it a second thought and just hook it up like the old one.
     
  13. Apr 18, 2017 #13

    nealtw

    nealtw

    nealtw

    Contractor retired

    Joined:
    Nov 4, 2010
    Messages:
    23,892
    Likes Received:
    3,117
    Have another look at plastic boxes.
    https://www.google.com/patents/US3119895
     
  14. Apr 18, 2017 #14

    bud16415

    bud16415

    bud16415

    Fixer Upper Staff Member Admin Moderator

    Joined:
    Feb 5, 2013
    Messages:
    4,654
    Likes Received:
    1,597
    It’s great someone patented one in 1968 but all the ones I have bought are all plastic expect for the two nails you use to attach them to a stud. When I go to the apron and vest stores they have barrels of the all plastic blue ones.

    Seems simpler to just ground the outlet or the switch and my guess is that’s why they added the ground screw to the switches.
     
    slownsteady likes this.
  15. Apr 18, 2017 #15

    Snoonyb

    Snoonyb

    Snoonyb

    Well-Known Member

    Joined:
    Sep 30, 2006
    Messages:
    2,899
    Likes Received:
    506
  16. Apr 18, 2017 #16

    nealtw

    nealtw

    nealtw

    Contractor retired

    Joined:
    Nov 4, 2010
    Messages:
    23,892
    Likes Received:
    3,117
  17. Apr 18, 2017 #17

    Snoonyb

    Snoonyb

    Snoonyb

    Well-Known Member

    Joined:
    Sep 30, 2006
    Messages:
    2,899
    Likes Received:
    506
    And there are a number of unknowns like, what is the dwellings age and in the boxes that do not appear to have a ground conductor, could it be in a romex that didn't have a grnd conductor or in the evolution of romex when an 18ga. bare copper was included and as often as not, simply cut off close to the strip.
     
  18. Apr 18, 2017 #18

    Snoonyb

    Snoonyb

    Snoonyb

    Well-Known Member

    Joined:
    Sep 30, 2006
    Messages:
    2,899
    Likes Received:
    506
    Every home desperado, low brow and ace have them.
     
  19. Apr 18, 2017 #19

    nealtw

    nealtw

    nealtw

    Contractor retired

    Joined:
    Nov 4, 2010
    Messages:
    23,892
    Likes Received:
    3,117
  20. Apr 18, 2017 #20

    Snoonyb

    Snoonyb

    Snoonyb

    Well-Known Member

    Joined:
    Sep 30, 2006
    Messages:
    2,899
    Likes Received:
    506
    I now understand your point of reference.

    Mite be a long drive, from PA.
     

Share This Page