Old light switch swap

Discussion in 'Electrical Forum discussion & Blog' started by sbcvulcan, Apr 7, 2009.

  1. sbcvulcan

    sbcvulcan New Member

    Messages:
    6
    Have an old two pole light switch that I'd like to update to my three pole. the wires attached currently are tan and red with the black capped. These colors have not been mentioned in any tutorials so i am hoping to get some guidance in wiring correctly. the two screws on the old switch are the same color also. I know the third pole is a ground on the new one.

    Thanks!:confused:
    ????
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,226
    Location:
    Cave Creek, Arizona
    switch

    Unless that "third pole" is a grounding screw you have the wrong switch. A switch with 3 "poles" would be a three way switch. When you only have two wires to the switch neither the color of the wire, or the pole you attach it to is relevent.
  3. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    You may not be correct in your identification of "poles". If your 3rd screw is green, it is a ground connection, and you do not have a ground wire. If on the new switch, two screws are brass colored, and one is black, that is a 3 way switch, and you have given us no idea that you have a 3-way situation.


    On the existing switch, "tan" is probably a white wire discolored by cigarette smoke etc. over the years. Whatever color the wire itself is, it is NOT a neutral wire if it is connected to the switch.

    We, and you,.....need to know a lot more about this situation to make a recommendation. Might be time to get in an electrician.
  4. sbcvulcan

    sbcvulcan New Member

    Messages:
    6
    sorry to refer as poles. there are three screws on the new one and one is the ground. It is the same type of switch just newer. THe tan is truly tan, not discolored. I've seen it through the house. Knowing this please advise.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,798
    Location:
    New England
    You have non-standard wiring as there is no tan wire in normal US domestic wiring for power, but the ground needs to go the ground terminal, the other two don't matter. All the switch does is connect those two together when you flip the switch on...doesn't matter which one is which - it's as if you twisted them together to turn the light on.

    It probably really IS white that has discolored with age.
  6. sbcvulcan

    sbcvulcan New Member

    Messages:
    6
    well can i safely assume the black is neutral and can be grounded or am i just safer taking those same two wires on the old one , hooking them up to new switch and leaving the black capped no grounding?

    okay on the discoloration, it is amazing how it all discolored so much but 50 yrs could do it i guess
  7. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689
    You can't safely assume anything.

    Install the new switch just like the old one was.
  8. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,529
    Location:
    North Carolina
    No the black is neither the grounded neutral nor the equipment grounding conductor.

    200.7 Use of Insulation of a White or Gray Color or with Three Continuous White Stripes.
    (A) General. The following shall be used only for the grounded circuit conductor, unless otherwise permitted in 200.7(B) and (C):
    (1) A conductor with continuous white or gray covering
    (2) A conductor with three continuous white stripes on other than green insulation
    (3) A marking of white or gray color at the termination

    250.119 Identification of Equipment Grounding Conductors.
    Unless required elsewhere in this Code, equipment grounding conductors shall be permitted to be bare, covered, or insulated. Individually covered or insulated equipment grounding conductors shall have a continuous outer finish that is either green or green with one or more yellow stripes except as permitted in this section. Conductors with insulation or individual covering that is green, green with one or more yellow stripes, or otherwise identified as permitted by this section shall not be used for ungrounded or grounded circuit conductors.

    It is very important that one understands the difference between the ungrounded, grounded neutral and the equipment grounding conductors. This is a process that will take more time than I am willing to give on a web site discussion forum.

    If you don’t understand the difference between the two then it would be a very good idea to keep you fingers out of the circuit as one could be instant death and the other is what will clear a fault and save your life. One is a current carrying conductor and the other should never have current on it.

    At any rate any wire other than green or white/gray is supposed to be hot and should never be connected where a green or white/gray wire is connected.
  9. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,296
    Location:
    Yakima WA
    All a 2 pole switch does is make or break the circuit connection. If you connected both the wires together, the light would be on, but of course you couldn't turn it off. Actually, both of these wires should be considered as "hot" and be black wires. The white neutral wire is connected directly to the light and is not switched. Old switches did not have grounds, but today, many lights require a ground so that is included. The ground lug is usually green and located on one end of the switch.
  10. sbcvulcan

    sbcvulcan New Member

    Messages:
    6
    I think I am good with the two screw swap but now i have uncovered the following.

    I have looked at two more switches in the house and guess what? None of them are wired the same as the other and different switches were used in two of them. I have an old hall light switch with three screws. One side has a red and black and the other side the tan/white. I hooked up my new switch exactly the way it was on the old switch and the breaker woud not turn on. (buzzed) I had to put it back together the way it was to make it work again.

    I also have three switches in one box and I dare not describe that.

    I guess i am close to giving up on this. the whole house is wired screwy anyways, there simply is no logic to the breaker setup and what they light.

    i appreciate all the replies.
  11. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,529
    Location:
    North Carolina
    Pray tell what do you mean you are going to give up?

    How many times have I heard that anyone can do this?
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,226
    Location:
    Cave Creek, Arizona
    switches

    When you work with switches you have to go by the terminals' functions, not how it compares to the old one, because the manufacturers do not necessarily have to make the new one look just like the old one. There is probably a logic to the wiring system, you just do not know it, and from what you are indicating, you might be wise to leave it alone. Especially if you are wiring switches in such a way that the circuit breaker "buzzes" or "hums". Oh, and you cannot ASSUME anything about wiring, and definitely not that any "black" wire would be a ground.
  13. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,296
    Location:
    Yakima WA
    You obviously do not have any experience with electrical wiring, and since you are confused about what you are encountering, I would urge to to hire a professional electrician. It is entirely possible that the previous own did some wiring incorrectly and makes it very difficult or impossible for a novice to figure out. Wiring, like plumbing, can be far more complex than it looks on the surface.
  14. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689
    Heh heh....there is some logic but you need to belong to a secret club to understand it. We have special handshakes and everything :cool:

    Call someone to help you out.:)
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