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Thread: Strong unpleasant whiff emitted at the end of life of a beloved compact fluorescent lamp...

  1. Top | #21
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    On a refrigerator the metal parts are connected to the third wire or safety ground. It 'Earths' or grounds exposed metal. If somehow the exposed metal contacts mains voltage a short circuit exists hopefully tripping a breaker.

    Back in the 59s-60s I remember there were appliances that would give you a tingle if touched the metal and a ground like a water pipe.

    A ground fault interrupter will detect small currents in the third wire and open the mains.

    Lamps these days do not typically have a third wire, Safety standards allow for it. What they have is a polarized plug.

  2. Top | #22
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    Quote Originally Posted by steve_bank View Post
    On a refrigerator the metal parts are connected to the third wire or safety ground. It 'Earths' or grounds exposed metal. If somehow the exposed metal contacts mains voltage a short circuit exists hopefully tripping a breaker.

    Back in the 59s-60s I remember there were appliances that would give you a tingle if touched the metal and a ground like a water pipe.

    A ground fault interrupter will detect small currents in the third wire and open the mains.

    Lamps these days do not typically have a third wire, Safety standards allow for it. What they have is a polarized plug.
    A GFCI doesn't detect the current in the third wire. In fact, its often used in older homes that don't have a third (ground) wire. The GFCI has electronics inside that compares the current on the hot and neutral of the outlet. If the two currents are the same (within a small amount), then all is OK. If there is a significant difference, that means current is leaking out on an unintended path (i.e a person or metal case), and so it trips.

  3. Top | #23
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    Quote Originally Posted by thebeave View Post
    Quote Originally Posted by steve_bank View Post
    On a refrigerator the metal parts are connected to the third wire or safety ground. It 'Earths' or grounds exposed metal. If somehow the exposed metal contacts mains voltage a short circuit exists hopefully tripping a breaker.

    Back in the 59s-60s I remember there were appliances that would give you a tingle if touched the metal and a ground like a water pipe.

    A ground fault interrupter will detect small currents in the third wire and open the mains.

    Lamps these days do not typically have a third wire, Safety standards allow for it. What they have is a polarized plug.
    A GFCI doesn't detect the current in the third wire. In fact, its often used in older homes that don't have a third (ground) wire. The GFCI has electronics inside that compares the current on the hot and neutral of the outlet. If the two currents are the same (within a small amount), then all is OK. If there is a significant difference, that means current is leaking out on an unintended path (i.e a person or metal case), and so it trips.
    Over here you will see GFI wall sockets in the bathroom and on kitchen counter sockets. It may save your life if you are taking a bath and drop a hairdryer in the water. I expect the National Electrical Code requires it around water.

    Above around 10 milliamps muscles contract and you can not let go. A circuit breaker upstream will not protect you. It is too slow and trips too high. Circuit breakers are primarily to prevent fire. 3 or 4 milliamps running from fingertips to fingertips can stop your heart.

    The National Electra Code specifies a max allowable current on the safety ground.

    https://simple.wikipedia.org/wiki/Re...current_device

    The National Electrical Code requires GFI in bathrooms and kitchens near water.

    https://www.ecmweb.com/code-basics/n...errupters-gfci

  4. Top | #24
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    Cold cathode lamps. The gas emits UV which causes fluorescence on a coating inside the tube. The radiation is not thermal induced. I can put my hand on a 25 watt bulb and it is barely warm.

    https://en.wikipedia.org/wiki/Cold_cathode

  5. Top | #25
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    Quote Originally Posted by thebeave View Post
    Quote Originally Posted by Speakpigeon View Post
    I guess that sounds as exactly it. Thanks.

    So, the mercury is a significant hazard, but hey don't seem to regard the smell as a problem. I closed and ventilated the room the whole night, so I was satisfied the gas emitted has mostly gone away. But I think I'll switch to LEDs, too, once I run out of the CFLs I have, though...
    EB
    I think the hazards from the mercury in the CFLs is a bit exaggerated. As I understand it, there is about a pin head sized amount of mercury...not enough to be worried about, unless maybe you're in the habit of eating CFL bulbs for lunch. Yet, here in California CFLs are supposed to be disposed of as hazardous waste, as though the environment and the human race is doomed if you just throw it in the trash.

    Another tip about the CFLs is that most are not designed to be used in an enclosed fixture (too much heat build up). This shortens the life, which is partially why it seems they don't last as long as they are advertised to last. Same with LEDs.
    interestingly, whether the lamp is mounted vertically or horizontally matters too, in terms of life (heat death).
    High Pressure Sodium lights (HPS) that are used for security (they are yellowish, and common in parking lots - and pot grow rooms, apparently) get extremely hot, and are specially rated for mounting vertically. Horizontal is the norm.
    So if your CFL is mounted vertically, it may lower life as well.

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