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How good is ETL safety certification?

Discussion in 'Electronic Basics' started by larry moe 'n curly, Dec 14, 2005.

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  1. I see appliances being sold now that lack UL or CSA approval markings
    and instead are only ETL certified.

    How good is ETL certification compared to those from UL and CSA?

    Does ETL require actual sample products to be submitted for testing, or
    are they like CE and let manufacturers work on the honor system (I have
    a CE approved multimeter rated for use at up to 500V, but its fuses are
    rated for only 250V, unlike a UL-approved Fluke).

    Are coffee makers required to be made of fire resistant plastic by any
    of the safety certification organizations? If so, which ones?

    I'm asking all this because I noticed that an ETL-approved drip coffee
    maker had only a bimetal thermostat to turn off the current while an
    older UL-approved coffee maker also had two thermal fuses in series..
     
  2. Dan Hollands

    Dan Hollands Guest

    In the late 80's law was passed to allow other than specification writing
    agencies to do testing to specifications such as UL

    See http://www.labconco.com/company/standards_certs/etl.shtml for more
    details.

    Of course one really has to know what specifications the product is being
    certified to.

    There are a multitude of UL and IEC specifications that cover different
    products and product applications.

    Dan

    --
    Dan Hollands
    1120 S Creek Dr
    Webster NY 14580
    585-872-2606

    www.QuickScoreRace.com
     
  3. Leo Yaus

    Leo Yaus Guest

    ETL certification is valid. Whether to use UL or CSA or ETL is a matter of
    cost, schedule, customer service, and factory location (proximity of facotry
    to service provider affects FUS [follow-up service] costs).
    ETL would require samples and documentation.
    CE is just a mark, not an organization. ETL (like UL and many others) can
    provide services permitting usage of the CE mark.
    Your meter rated at 500V but having 250V fuses is not odd. These fuses are
    for overcurrent protection, and 250V is the highest nominal value for
    commonly available replacement fuses.
    Coffee makers require flame retardant plastic (94-V0 or V1). Standard is
    EN60335?
    Thermostat versus two thermal fuses is an individual manufacturer's design
    consideration. Either of these or other protection methods are valid as
    long as all of these test in the standard(s) can be met.
     
  4. Is there a chance that a fuse with a too low a voltage rating can
    explode violently enough to pierce through the case? I noticed that
    the 600V fuse in a Fluke meter was enclosed in woven fabric, possibly
    for such a rupture.
    I thought a coffee maker would be required to have a backup means of
    shutting off the current in case the bimetal thermostat failed because
    back in the 1970s or 1980s there was a big lawsuit against GE when
    thermostats in some of its coffee makers failed and caused fires.
     
  5. SQLit

    SQLit Guest


    Back up>>>> your joking. I have had it with most of the coffee makers on
    the market. I plug them in in the morning and unplug them when done. Tired
    of the crappy el-cheapo stuff. If it aint plugged in it certainly will not
    hurt anything.
     
  6. SQLit

    SQLit Guest


    Back up>>>> your joking. I have had it with most of the coffee makers on
    the market. I plug them in in the morning and unplug them when done. Tired
    of the crappy el-cheapo stuff. If it aint plugged in it certainly will not
    hurt anything.
     
  7. :
    : Leo Yaus wrote:
    :
    : > Your meter rated at 500V but having 250V fuses is not odd. These
    fuses are
    : > for overcurrent protection, and 250V is the highest nominal value
    for
    : > commonly available replacement fuses.
    :
    : Is there a chance that a fuse with a too low a voltage rating can
    : explode violently enough to pierce through the case? I noticed that
    : the 600V fuse in a Fluke meter was enclosed in woven fabric,
    possibly
    : for such a rupture.
    :
    : > Coffee makers require flame retardant plastic (94-V0 or V1).
    Standard is
    : > EN60335?
    : > Thermostat versus two thermal fuses is an individual
    manufacturer's design
    : > consideration. Either of these or other protection methods are
    valid as
    : > long as all of these test in the standard(s) can be met.
    :
    : I thought a coffee maker would be required to have a backup means of
    : shutting off the current in case the bimetal thermostat failed
    because
    : back in the 1970s or 1980s there was a big lawsuit against GE when
    : thermostats in some of its coffee makers failed and caused fires.

    I've had the delightful experience (~1980) of being in a computer lab
    next to an office where someone left one of those things going, when
    they left for the day. An unforgettable experience...by the time we
    could smell the smoke in the lab, the office was completely engulfed
    in flames.

    Are they really any safer, now? Seeing the efforts big business has
    been making to remove government oversight where it can, I'm not
    terribly confident about that.
     
  8. TKM

    TKM Guest

    UL isn't government. From my experience (mostly residential lighting
    equipment), I haven't noticed any relaxation of standards for fire or
    electrical safety. If anytthing, It has been just the opposite.
    Competition appears to be good for UL. Manufacturers have options including
    ETL and CSA (Canadian Standards Association) and others so there are
    alternatives. That helps costs and speed of testing. They all test to the
    same standards. Some lighting equipment standards are now tri-national (US,
    Canada and Mexico).

    TKM
     
  9. :
    : : > : > :
    : > : Leo Yaus wrote:
    : > :
    : > : > Your meter rated at 500V but having 250V fuses is not odd.
    These
    : > fuses are
    : > : > for overcurrent protection, and 250V is the highest nominal
    value
    : > for
    : > : > commonly available replacement fuses.
    : > :
    : > : Is there a chance that a fuse with a too low a voltage rating
    can
    : > : explode violently enough to pierce through the case? I noticed
    that
    : > : the 600V fuse in a Fluke meter was enclosed in woven fabric,
    : > possibly
    : > : for such a rupture.
    : > :
    : > : > Coffee makers require flame retardant plastic (94-V0 or V1).
    : > Standard is
    : > : > EN60335?
    : > : > Thermostat versus two thermal fuses is an individual
    : > manufacturer's design
    : > : > consideration. Either of these or other protection methods
    are
    : > valid as
    : > : > long as all of these test in the standard(s) can be met.
    : > :
    : > : I thought a coffee maker would be required to have a backup
    means of
    : > : shutting off the current in case the bimetal thermostat failed
    : > because
    : > : back in the 1970s or 1980s there was a big lawsuit against GE
    when
    : > : thermostats in some of its coffee makers failed and caused
    fires.
    : >
    : > I've had the delightful experience (~1980) of being in a computer
    lab
    : > next to an office where someone left one of those things going,
    when
    : > they left for the day. An unforgettable experience...by the time
    we
    : > could smell the smoke in the lab, the office was completely
    engulfed
    : > in flames.
    : >
    : > Are they really any safer, now? Seeing the efforts big business
    has
    : > been making to remove government oversight where it can, I'm not
    : > terribly confident about that.
    :
    : UL isn't government.

    Never said they were. UL doesn't make the laws, you know? What I'm
    saying, is that big business always has, and always will try to make
    an endrun around the rules, if it seems profitable, especially if it
    looks like no one will ever catch them.

    : From my experience (mostly residential lighting
    : equipment), I haven't noticed any relaxation of standards for fire
    or
    : electrical safety. If anytthing, It has been just the opposite.
    : Competition appears to be good for UL. Manufacturers have options
    including
    : ETL and CSA (Canadian Standards Association) and others so there are
    : alternatives. That helps costs and speed of testing. They all test
    to the
    : same standards. Some lighting equipment standards are now
    tri-national (US,
    : Canada and Mexico).

    Even if UL or some other agency has tested the products, there is
    still room for poor QA...and some people cheat, when it comes to
    keeping to the standards, too. Just because something you're familiar
    with doesn't appear to have any problems, doesn't mean there aren't
    any, either.
     
  10. TKM

    TKM Guest

    Of course. But there are data. Injuries and deaths from electrical shock
    and fires for one. These have remained just about constant even though the
    population has increased and has become less aware of electrical hazards (my
    view). The CPSC opened an investigation of electrical/lighting fires last
    year and is even paying a $50 "bounty" to fire departments to file reports.
    Nothing significant so far.

    What I see as the main problem at the moment is fake and counterfeited UL
    (and other) marks placed on products, mostly imported, that haven't been
    inspected or built to standards. Major manufacturers are paying extra to
    CSA, for example, to do "dock" inspections overseas to ensure that what's in
    the container is what they ordered including proper standards marking.

    But where does the fake stuff end up -- on the internet, in "dollar" stores?
    I don't know.

    TKM
     
  11. not i

    not i Guest




    Many 600 volt fuses are available. The meter I use has 600 volt fuses
    and they are readily available in the area I live.
     
  12. Are 600V fuses that are no more than 3/4" long? That's all the room
    there is for a fuse in my meter.
     
  13. How do you rate a fuse for voltage? It would be a peculiar design that
    would flash over between terminals even at 500 volts.
     

  14. Really? Then try a 32 volt automotive fuse at 500 volts. PS, make
    sure you can pull the plug or kill the main braker before you grab the
    fire extingisher.
     
  15. Really? Even an 1 1/4" 'automotive' fuse?
     
  16. Rich Grise

    Rich Grise Guest

    "Voltage Rating
    The maximum voltage at which a fuse is designed to operate. Exceeding
    the voltage rating of a fuse impairs its ability to clear an overload or
    short circuit safely. Fuse can be used at any voltage below the fuse
    voltage rating; a 250V fuse can be used in 125V circuits. Voltage
    ratings are assumed to be for AC unless specifically labeled as DC."

    -- http://www.circuitprotection.ca/fuseology.html#VoltageRating

    Cheers!
    Rich
     
  17. Bud--

    Bud-- Guest


    Really? Even an 1 1/4" 'automotive' fuse?
    [/QUOTE]

    The US old style glass tube automotive fuses when burned open won't
    flash over at 500 volts. But if connected to a 500 volt circuit, when
    they open the melting metal will likely vaporize and the conductive
    plasma created will continue the conduction. The energy released would
    likely cause the fuse to explode - not acceptable for most users. On
    high available current circuits the plasma could go end to end causing
    conduction for a relatively long period. The arc can vaporize more metal
    feeding the plasma. This can cause a large explosion with flying shrapnel.

    US fuses have not only a voltage rating but a rating for the maximum
    current the fuse will interrupt. If the circuit has an available fault
    current higher than the fuse interrupt rating the fuse can also explode,
    even though the fuse is used within its voltage rating. I expect you
    have the same thing over the pond.

    Multimeters are rated for where in a power circuit they can be used,
    like downstream from a panel (lower avalilable fault current) or on
    service wires (high available fault current). This is based on the
    design as in the paragraph above. I believe this is an IEC standard.

    bud--
     
  18. Bud--

    Bud-- Guest

    More particularly related to voltage:
    When a fuse opens there will be an arc. The arc will have a voltage
    across it. 32 volts will not support a very long arc. 500 volts will
    suport a much longer arc and will be a lot harder to extinguish. As fuse
    material is vaporized (as opposed to just ionized air) the resistance of
    the arc will go down and an arc with a voltage drop of 500 volts across
    it will increase and be even harder to extinguish.
     
  19. The interrupting capacity of a typical 1.25" Fast-Acting 3AG fuse at
    250V is MUCH lower than at 125VAC. They will interrupt 10kA at 125V,
    but only more like THIRTY-FIVE amps at 250V. Check out the data
    sheets.

    Put them in a situation where they can see thousands of amperes fault
    current @240V and they can and often do EXPLODE, rupturing the glass
    and sending fragments everywhere.

    Of course the 20mm types are worse again.

    That's why Fluke multimeters use a much larger fuse.

    During failure of the 3AG type fuses, the melted metal ionizes inside
    the fuse and allows an arc to form directly from one end cap to the
    other, which has very low impedance (low voltage drop, but lots of
    watts for such a small enclosed space).


    Best regards,
    Spehro Pefhany
     
  20. Ralph Mowery

    Ralph Mowery Guest

    All fuses (of any qulaity) are rated for a maximum voltage. Also not usualy
    in big letters they will have a maximum current they can inturrupt. While
    looking at the physical size of them, they all look the same. I don't know
    what the differance is in them, but there must be. I was in a class put on
    by one of the fuse makers. They said that at one time one of the selling
    points for so many differant kinds of fuses it that they are made for a
    specific purpose. Now they have reversed the thinking (selling point) that
    one fuse will replace many fuses that are similar.

    It is really interisting to watch the Fluke meter film on using the wrong
    fuse in a circuit.
    Nice demonstration of what can hapen if you hook you meter across the
    circuit while in a current or ohm range when you really mean to measuer the
    voltage.

    At work I look in the cabinet with fuses and see about 10 differant fuses
    that are almost the same size and ratings. Some will have slightly
    differant tips on them so you can not use them in the some fuse holders.
    Really bad to have to stock so many differant kinds.
     
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