Double switch conversion/power grab/need advice

Discussion in 'Electrical Forum discussion & Blog' started by Cherrie, May 10, 2021.

  1. Cherrie

    Cherrie New Member

    Joined:
    Apr 6, 2021
    Location:
    Spanaway, WA
    Good afternoon everyone! I'm a new member (and this is my very first post) but I have been here looking for answers to my plumbing questions countless times over the past several years and this forum has never let me down, so the moment I realized I needed some expert electrical advice with my current wiring project I came straight here . I'll explain my situation but there's something you should know before I do and although I am well aware that by telling you this I may become the subject of ridicule and distain, viewed with the same disregard one might have for a bug they've just has squashed under their shoe or perhaps just dismissed entirely - relegated to the level of red-headed stepchild for all eternity - nevertheless, in the interest of full disclosure you should know...this is a manufactured home... (I know, I know! I'm SORRY!)

    Okay, now that the cat's out of the bag (and you've had sufficient time to roll your eyes and mutter a few colorful words under your breath) please allow to me describe my situation... The exhaust fan and the overhead light in my bathroom are controlled via a "double switch". I am eliminating that switch and replacing it with two separate switches - a "spring wound" timer switch for the fan and an illuminated rocker panel switch for the overhead light. There are two cables in the switch box, a 2 wire cable (black/white, not including ground) that brings power from the panel and a 3 wire cable (black/white/red, not including ground) going from the double switch to the exhaust fan and the overhead light. I also want to grab power from this switch box to install a new receptacle/GFCI that I need near the toilet. I have attached a diagram of what I think is the correct way to wire the new setup. I think I went a bit overboard with my drawing, my hand just kept drawing what my brain was envisioning so please take note of the large dotted line running through the middle of the diagram, everything above the line is not visible to me - it's just a drawing of the way I suspect that it's wired. Everything below the dotted line is the wiring plan I'm proposing and that I need input and advice on before proceeding because it's entirely possible that I've got it all wrong and contrary to what most people who know me believe, the "no guts no glory" approach is not the only one I know - I am in fact capable of exercising a little caution and playing it safe and yes, even asking for help. I would be extremely grateful for your assistance and any input, advice, guidance or direction you can offer. Thank you so much!


    Bathroom Wiring Diagram.jpg
     
  2. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    Are there in fact more fixtures controlled by the same light switch?

    Otherwise, your beautiful drawing looks correct except I think you've mirror imaged the GFCI (i.e. the neutral wipers are on the left when looking at the face of the receptacle).

    And of course, all the cables should have EGCs, all EGCS should be connected together in every enclosure, and work should only be done with the power shut off at the breaker.

    Cheers, Wayne
     
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  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    If you don't have ground wires, the receptacle should be labeled with "No equipment ground", sticker, which is probably in the box with the GFCI. It would be better with an actual EGC, but legal, if labeled properly for retrofit.

    If you wanted to protect the other devices from the GFCI, you'd break the hot and neutral connections, run the ones from the panel to the GFCI line inputs, then run the load outputs back to the connections to power the existing stuff. Some older stuff, may have problems being protected by the GFCI, but if they did, they should probably be replaced, anyway.
     
  5. Cherrie

    Cherrie New Member

    Joined:
    Apr 6, 2021
    Location:
    Spanaway, WA

    Thank you for the replies. My apologies for not acknowledging them sooner but it took me longer than I thought it would to find out exactly what was going on above that "dotted line" in my original diagram (you may recall my saying that that area was not actually visible to me but I was drawing it the way I thought it was likely to be). Now hold on! I know what you're thinking - something along the lines of "WHAT?!?! Are you BRAIN DAMAGED?!?! You don't GUESS with electricity! It's NOT a GAME! Electricity can KILL YOU! Do you GET THAT???" or something to that effect. But you don't have to worry, I actually understand perfectly and was definitely NOT going to actually DO anything until I knew with complete certainty what was actually going on above that "dotted line." I have a tendency to be rather impatient when I want to do something and I also happen to be night owl. I was just anxious to know if my wiring diagram was correct (if what I thought was going on above the "dotted line" turned out to be true) and it happened to be getting rather late so I took a break from tracking all the wires down, made the drawing and then posted it thinking that maybe by the time I finished tracing everything and if it turned out to be what I thought it was, there was a good chance that I'd have gotten a reply and providing my proposed wiring plan was met with approval I would be able to get started right away.

    After I posted it I went right back to tracking the wires down and it took longer than I thought it would. In the meantime, I received a reply from Wayne but by then I'd gotten far enough to know that my original theory about what was going on was NOT correct. It would have been better had I just waited until I absolutely knew for a fact what the wiring situation was before I posted anything and I didn't want to make any more assumptions so I waited to respond to your replies until I had the facts - which I now do - with 100% accuracy. I've been into my walls and my ceiling, I disassembled the bathroom exhaust fan (and put it back together), traced the wires, mapped the entire circuit and determined where my light and fan are located in it.

    Now that I've actually done what I should have done before posting in the first place, I still need some advice and would be grateful for any input you can give me. I've attached a new drawing which shows the actual wiring that exists.

    A few notes re the drawing:

    The white/neutral wires are drawn in blue for the sake of clarity.

    The ONLY hot (always on) wire coming into the switch box is the black wire in the 3 wire cable from the ceiling box for the light.

    I have left the ground wires out of the diagram just to keep it easier to follow but I fully understand that all the cables should have EGCs (they do) and all EGCs should be connected together in every enclosure (they are and they will be).

    The original double switch that the fan and light were wired to has been removed but there is a separate diagram of it showing exactly how it was wired before I took it out (see bottom right corner of diagram).

    I had two goals with this project - the first was to eliminate the double switch (which I REALLY do not like) and replace it with two separate switches and the second was to install a new GFCI/receptacle near the toilet. The fan and light are the last two fixtures on the circuit which, if I am not mistaken, puts a definite crimp in my original plan to grab power for the GFCI from the fan/light switch box.

    Is there any way that can still be accomplished? if anyone has any suggestions, please tell me, one way or another it's critical that I get the GFCI installed. A couple of questions about that - if I could run a cable from the ceiling box to where I want the GFCI, would that work? If yes, how? Also, there is an receptacle on the other side of the wall that the fan/light switches are located, it is on the same circuit and obviously it would be a middle of run but for reasons I won't bother explaining, it would be extremely difficult to access it.


    Revised [Dwg is now completely accurate].jpg
     
  6. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    You can still do what you want. The 3 conductor cable from the ceiling light box to the wall double gang has a neutral (white) and a constant hot (black). [And the red is switched hot for the light.]

    So you can just run a new 2 conductor cable from the wall double gang box to your new receptacle location, and connect the neutral/hot in the new 2 conductor cable to those two conductors in the 3 conductor cable.

    Cheers, Wayne

    P.S. I assume that the fan is not directly over the tub or shower? If it is, then the manufacturer's instructions almost certainly require it to be on a GFCI protected circuit. [You could determine the model number, find the instructions, and check. It may be that if your ceiling is high enough, GFCI protection is not required.] And if so, then it is worth checking whether the circuit is already GFCI protected.

    If it is, you can use a regular receptacle for your new receptacle (and now you'll know where to reset the GFCI). If it is not, you can GFCI protect the fan by adding two 2 conductor cables from the double gang wall box to the new GFCI receptacle. One cable would provide power to the receptacle, and the other cable would return GFCI protected power to the wall box, to supply the fan through the timer. The pre GFCI and post GFCI circuit conductors (in particular the neutral) would be kept entirely separate in the double gang wall box.
     
  7. Cherrie

    Cherrie New Member

    Joined:
    Apr 6, 2021
    Location:
    Spanaway, WA

    Thanks, Wayne!
    That is awesome news - best possible scenario for me. The fan is in the middle of the ceiling and not directly over anything with water. I actually installed that fan myself 8 years ago when I bought this place (I just replaced the dismal excuse for fan that was already there - and when I call it a "fan" it's only because I have no idea what to call something that is supposed to move air but is utterly useless at actually doing it). I replaced the light some time ago as well but like the fan upgrade, no new wiring was involved. I've been chomping at the bit to get rid of that double switch though and needing to get power from the switch box for the GFCI gave me the perfect opportunity to kill two birds with one stone. The circuit is not GFCI protected. There is a GFCI protected outlet by the sink but it is on a different circuit.

    I've attached a diagram based on what you said in the first part of your previous reply. The drawing is pretty messy at this point though (notice that I added all the grounds in just so you could see them), Did I interpret what you said correctly? Do you see anything wrong in the diagram or did I miss anything? I'm standing by until you tell me I've drawn it out correctly (if I mess it up in actuality, that's on me). Thanks a bunch for all your patience and your very kind assistance, you've been such a huge help.

    Cherrie

    p.s. You don't happen to be a plumbing expert as well, do you? I've got a project in that department that I put temporarily on hold to get this one done. I was working on a drawing of my proposed plumbing layout when this came up. GFCI Wiring Final.jpg
     
  8. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    Drawing looks good. Wayne
     
  9. Cherrie

    Cherrie New Member

    Joined:
    Apr 6, 2021
    Location:
    Spanaway, WA
    That's great! I appreciate your help more than I can say. I can't thank you enough!

    Cherrie
     
  10. alfredeneuman

    alfredeneuman New Member

    Joined:
    Dec 12, 2020
    Location:
    fullerton, ca
    What do you intend to plug into the GFI? What ampere rating is the circuit breaker?
    I'd be suspicious of tripping the breaker if it is something like a hair dryer.
     
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