AC Noob Help Please...

Discussion in 'General Electronics Chat' started by Brian Hedger, Jul 6, 2015.

  1. Brian Hedger

    Thread Starter New Member

    Jul 6, 2015
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    I'm making custom dimmer switches for my antique lamps. I'm taking a rotary style dimmer switch and putting it within a small aluminum enclosure. I'm using a 3 wire cord with a 3 prong plug.


    My question is, will a metal enclosure around the dimmer switch leading to the light be safe to sell to customers if I fasten and solder the ground wire to the metal enclosure that's holding the rotary dimmer switch? Or is it advised/ the law to make AC appliances/dimmers with plastic enclosures?

    Thank you, if you're confused about what I'm working with, I attached an example of the dimmer switch and the enclosure.
     
  2. Lestraveled

    Well-Known Member

    May 19, 2014
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    If you install the dimmer unmodified, then you will have a stronger defense if you are sued, if your lamp causes a fire or kills someone.
     
  3. Brian Hedger

    Thread Starter New Member

    Jul 6, 2015
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    by unmodified are you meaning not tampering with the actual dimmer? I can still put it in a metal enclosure?
     
  4. Brian Hedger

    Thread Starter New Member

    Jul 6, 2015
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    is a metal enclosure safe/legal for an AC consumer electronic appliance?
     
  5. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    It appears that you are trying to make an inline lamp cord dimmer to sell. Those can be bought for ~ $10US. And why install 3-wire cords on antique lamps?

    Ken
     
    Last edited: Jul 6, 2015
  6. Brian Hedger

    Thread Starter New Member

    Jul 6, 2015
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    they're antique lamps but they're customized. they are metal, and I'm concerned that with mishandling a wire would come loose and touch the metal frame shocking the customer. would I then attach a ground wire to my custom metal enclosed dimmer switch is what I'm asking...
     
  7. mcgyvr

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    All metal that "could" be exposed to electricity in the event of a fault MUST be grounded.
     
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  8. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Based on what you have described, it sounds ok. BUT - this is not a legal advice column. The only way to know for sure is to have your device tested by a national testing lab (NTL) such as UL. The standard that might govern this type of product is UL1950 / UL60950 / EN60950 or some other version that has similar paragraphs. They might require one or more of these tests on every unit produced:

    Leakage Current - Test of the maximum current through the earth ground conductor.
    Ground Bond Test - Resistance test to insure the integrity of the connection between the earth ground wire and your device. A typical requirement is 2.5 milliohms or less.

    ak
     
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  9. KMoffett

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    Dec 19, 2007
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    A ground is not required on the metal parts of "lamps". Walk through any furniture, department, or Big Box store and note that most (if not all) table or floor lamps have two-wire power cords. Also note that the power cords have UL or similar tags. Those mean that just the cords have approval. Yes, if they have 3-wire cords, the metal parts should be grounded to the third wire.

    Ken
     
  10. mcgyvr

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    Yes because the nature of their design (be it double/reinforced or secondary insulation) and method of production/assembly has been approved by UL to not require grounding.

    The OP already stated he was worried that wires could contact the box.. Hence he "should" ground the box if he cannot guarantee/ensure safety. Since he is already a self-proclaimed "noob" he should attach the ground wire.
     
  11. Brian Hedger

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    Jul 6, 2015
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    In order to sell these products to stores I need to get them tested by UL? Would this product still need to be tested with a plastic enclosure?
     
  12. BillB3857

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    Feb 28, 2009
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  13. KMoffett

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    If the UL donuts are on the cord, only the cord set is UL approved. If on the socket, only the socket is approved. If the OP can't be sure that the wires inside the metal box won't touch, anything that they do will be suspect. All this indicates to me that the OP should purchase off the shelf dimmers. Trying to spoon feed a total NOOB through the design process for something that they want to sell is wrong, when cheap, off the shelf solutions already exist
    Ken
     
  14. Brian Hedger

    Thread Starter New Member

    Jul 6, 2015
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    The design and wiring set up is done, I know how to design and connect a dimmer switch and insulate it properly. I can make a better looking dimmer then the ones you guys want me to buy. These are specialty fans and I'm making dimmers that match the stained and engraved metal on my fans. So the business and its purpose is irrelevant to the question.

    I just need to know, is a metal enclosure for an AC appliance ok if I secure the ground wire to the metal enclosure?

    And am I going to need to get my dimmers checked to ensure it meets UL standards?
     
  15. KMoffett

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    So it's changed from lamps to fans?

    Ken
     
  16. Brian Hedger

    Thread Starter New Member

    Jul 6, 2015
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    I do both fans and lamps, I apologize for putting fans, I'm asking about the lamps.

    Ken, I'm assuming you're the forum douche bag.
     
  17. #12

    Expert

    Nov 30, 2010
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    We take turns. :D
     
  18. #12

    Expert

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    1) Yes.
    2) People with a lot to lose and a lawyer will not accept my opinion. You will still need somebody with more clout than I to satisfy the retailers.
     
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  19. Lestraveled

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    May 19, 2014
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    Whenever you take an appliance and modify it, and then sell it. You are liable for that appliance forever, or until someone else modifies it, then they, are liable for it. It does not matter how many times it gets sold, you still are liable because you modified it. The best way to deal with this liability is to get liability insurance, which is far cheaper then having a testing lab certify your lamp. It does not matter that your work is perfect and fully complies with electrical codes. If your lamp or fan is involved in a fire and there is a paper trail to you, then you can expect to be sued. You need to think about these things and do the things necessary to protect youself.

    As far as what to ground, do searches on appliance standards, grounding and electrical safety standards.
     
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  20. mcgyvr

    AAC Fanatic!

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    Must you get UL approval?.. No
    Could you? Yes..
    Might you have trouble selling the product to stores/consumers because you don't have it?.. Yes you could
    Could you be liable for any safety/fire/shock related issues? Yes
    Should you ensure that the type of business you start (LLC, S Corp, Sole Pro,etc..) is appropriate and not allow you to be personally held liable? Yes
    Could the wrong business type allow your house to be taken and all your personal possessions should something happen? Yes

    Should a metallic object that may become energized in the event of a fault be grounded? Yes
    Are their methods to not require grounding? Yes
     
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