Nuts and Volts

Discussion in 'General Electronics Chat' started by inwo, Nov 24, 2013.

  1. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    2,433
    315
    Check out the Christmas Can Light Dimmer/ Santa Clause Killer project.

    Life time subscriber.
    Never felt the need to give feedback before.

    Is this a joke.

    One of the lines is connected to a can under the tree.
    Author called it a "ground". It's the neutral, aka grounded current carrying conductor.

    THERE IS NO GROUND IN A ZIP CORD!:eek:
     
  2. DerStrom8

    Well-Known Member

    Feb 20, 2011
    2,428
    1,328
    Not being a subscriber myself, I have no idea what you're talking about :p

    Could you provide a better description of the setup please?
     
  3. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    2,433
    315
    Sorry, I didn't give this post much thought.
    I'll look for a link to online version.

    Simple project for dimming Christmas tree lights.
    Seemed too simple for a magazine like N&V.

    Author mounts a dimmer switch in a soup can :rolleyes:, Connects a lamp cord in and out with appropriate 2wire line voltage plugs.

    A romex connector is used to protect the wires.

    One of the romex connector screws seemed like a good place to terminate one of the conductors.

    In fairness, author did suggest using the grounded one.
     
  4. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    2,433
    315
  5. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    I thought the same thing: pretty lame excuse for an article. I used to write for gun mags, and have been thinking about submitting something to N&V. Looks like they are in need.
     
  6. GopherT

    AAC Fanatic!

    Nov 23, 2012
    5,991
    3,737
    How much do magazines pay for articles (how do they pay - negotiated individually, by the page, ...?).
     
  7. JoeFromOzarks

    Active Member

    Apr 14, 2010
    95
    27
    This may be the most scary project ever!!!

    http://www.designnews.com/video.asp...htid_66,vsid_321,aid_266522&dfpLayout=videoBC

    Gadget Freak Case #245: The Programmable Crock-Pot

    Bernard Smith created a timer that offers a delayed start, so that a slow cooker can begin cooking while everyone is out.


    WHAT? :eek:


    /sarcastic_on "I know, let's make an 'invention' that will create bacteria infested crock pot dinners!!" /sarcastic_off

    It just beats me. Just beats me silly, what some people can come up with, with a little electrical tape properly misused, and then video themselves.



    :) joe
     
  8. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    I've got a few dimmers like this: a zip extension cord, a standard light dimmer, and a plastic work box. Cover optional (as I didn't bother with one).

    Stick the zip cord into the box, cut access for the dimmer, USE THE WIRE NUTS that come with the dimmer (no tape). Slide dimmer into workbox, screw it down and done.

    Have a few of these so the tree doesn't become blindingly bright.

    As long as you keep hot and neutral correct I don't see any safety issues with this.

    (Note: Detailed directions are NOT available. If you even need what I presented here to co this you do not have enough experience to be safe.)
     
  9. Metalmann

    Active Member

    Dec 8, 2012
    700
    223
    That setup will be fine.
     
  10. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    2,433
    315
    What I think you mean, is that yours is safe. Seems so! With the exception of not being grounded.
    A metal box would not be safe without a three wire cord, which is what I use on my controls. Even with plastic boxes, the cover screws could become energized.

    The point I want to make, as I thought it would be obvious in an electronic forum, is that there is no difference between the two current carrying conductors in circuit design.

    However it is good practice and code, to put switches and controls on the hot leg.

    Polarized plugs can be miswired or defeated.
    Most modern outlets are polarized. They are often miswired.

    Even if the N&V design was wired as shown, with the neutral grounded, a miswired outlet would put the can at line voltage.

    A bad circuit neutral connection would allow the "hot" to feed thru load and energize the can.
     
  11. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    No, my lash up doesn't need a cover. You have no way to tell that as I am not providing any details, suffice it to say the particular dimmer I use also works as a finger safe cover.

    With lighting circuits it is often safer to keep neutral on the correct line. Guess which piece of metal is neutral in an Edison socket?

    Barring a miswire it is never less safe to keep neutral on the correct side.
     
  12. scoobydoo

    New Member

    Nov 25, 2013
    8
    1
    Conceptually its okay except that he butchers the wrong extension cord. Like others have pointed out the box is metal so by code it has to be grounded. Using a 14/3 extension cord would be better. Myself I would do the same thing except use proper 14/3 cable and plugs/receptacles. Of course there is the bacteria issue but that's a health issue and not covered by the electrical code:rolleyes:
     
    inwo likes this.
  13. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    2,433
    315
    Are you talking about the article?

    If so, I'd like some feedback on using the "possible" neutral for a ground.

    Maybe the danger is so obvious that it doesn't provoke comment.:confused:
     
  14. GopherT

    AAC Fanatic!

    Nov 23, 2012
    5,991
    3,737
    Three conductor cable is so common and, if you are using s metal box, there is no reason to skip the ground. Depending on the current, the conductivity of your wire and any induction picked up by your conductor - your "ground" may be several volts to 10s of volts above your panel's ground. Not too scary but not really ground either.

    In the end, you are really relying on some electricians helper or a previous homeowners DIY skills. Do you want to do that? How sure are you that neutral is neutral? How sure are you that the black wire is screwed into the brass colored screws on each outlet? How sure are you that your project will never be moved to another house with the same questions?
     
  15. Metalmann

    Active Member

    Dec 8, 2012
    700
    223
  16. #12

    Expert

    Nov 30, 2010
    16,257
    6,757
    I won one of those as a door prize at a Speed Queen laundry equipment training seminar in 1972. It's still in my everyday bucket and it has paid for itself many times over.:p
     
    Metalmann likes this.
  17. #12

    Expert

    Nov 30, 2010
    16,257
    6,757
    Wire number one = the expected voltage (compared to earth) and a current carrying conductor. I will call that, "hot" in this post. Hot always has a fuse or circuit breaker in series with it.

    Wire number 2 = "neutral" a current carrying conductor connected to earth ground at the breaker box. Neutral never has a fuse or circuit breaker in its path.

    Wire number 3 = a conductor that is connected to earth ground at the breaker box, but not intended to carry current except in case of a fault. Electricians call it, "bond". Bond never has a fuse or circuit breaker in its path.

    Under normal conditions, the current from the hot wire returns to the mains transformer through the neutral wire. Both of these wires have some resistance, and so the voltage applied to the load is a bit less than it was at the breaker box and the voltage on the neutral wire is not zero until you get all the way back to the breaker box. Meanwhile, the bond wire has no current and no voltage. It's connected to the metal boxes, shields, and whatever protective covers on electrical equipment. But, you already know this.

    The danger lies in the fact that the neutral wire is never at 0.000 volts when current is flowing in the hot wire. If neutral is mistakenly connected to a metal shield, that "protective" shield will have a voltage on it. If you are standing barefoot on concrete, and touching the metal shield, you can feel this voltage when a motor starts up. There are ways to connect the wires incorrectly so that neutral is connected to the metal boxes and shields. This mistake might be in the wall outlet. This mistake might be at the load end of the multi-conductor cable.

    Have I described what you want to know?
    Please respond if I did not understand your question.
     
    inwo likes this.
  18. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    2,433
    315
    That's what I was looking for.

    For a while I was thinking, "is it only me that sees an obvious safety hazard".
    ie. neutral conductor is not a ground. Even though it is grounded.
     
  19. musicalavtech

    Member

    Mar 23, 2012
    32
    3
    Having worked for an electrical contractor before, we were schooled the hot goes to the load/device first...then switched. Not that I know code these days.
     
  20. #12

    Expert

    Nov 30, 2010
    16,257
    6,757
    So, your customers can be killed while changing a light bulb, even if the wall switch is turned off? Must be confusing to them.:D
     
Loading...