problem with ceiling light fixture

Discussion in 'Electrical and Wiring' started by jacobc, Sep 27, 2011.

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  1. Sep 27, 2011 #1

    jacobc

    jacobc

    jacobc

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    I have a Keystone ceiling light fixture that uses two concentric circular fluorescent bulbs. For a number of years it worked fine, but a year ago both light bulbs burned out. I replaced the bulbs, but recently the fixture started having problems again, namely it refused to turn on when the switch was flipped (would blink and go out again) and it would take several tries to turn it on (and sometimes it refused to turn on entirely). I bought another pair of light bulbs and opened it up, at which point I found that (a) one of the old bulbs was totally burned out, while the other one still worked but looked like it was getting close to burning out, and (b) one set of connecting cables from the power box worked, but the other didn't. I changed the larger (32W) bulb and connected it to the working connectors, and left the broken connectors loose (I left the burned out smaller [22w] bulb in the fixture just to take up space). But now (a week later) the fixture is doing the same thing: blinking and refusing to turn on when the switch is first flipped, so that it takes multiple flips back and forth to turn it on. Clearly there is something wrong with the fixture itself. What would you recommend doing? And is this something a person who is not particularly handy or experienced can do themselves? I'm attaching a picture to show what the fixture looks like. Thanks a lot for your help.

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    IMG_8662.jpg

    IMG_8666.jpg
     
  2. Sep 27, 2011 #2

    kok328

    kok328

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    Most likely the ballast has gone bad. I would recommend replacing the entire fixture.
     
  3. Sep 28, 2011 #3

    gatorfan

    gatorfan

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    Technically you could replace the ballast, but it will probably be more expensive. I'm with kok328: replace the whole fixture.

    Matt
     
  4. Sep 29, 2011 #4

    jacobc

    jacobc

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    Thank you for the replies. Is the fixture easy to replace, given that I have pretty much no experience in electrical / wiring work?

    Another thing I've noticed is that the light fixture in the living room (next to the kitchen), which uses incandescent light bulbs, also seems to burn out the bulbs much faster than it should. Is it possible that there is a bigger wiring problem in the apartment that's affecting both light fixtures?

    Thanks again.
     
  5. Sep 29, 2011 #5

    kok328

    kok328

    kok328

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    Apartment? If this is a rented apartment, you should have all repairs handled by your landlord.
     
  6. Sep 29, 2011 #6

    gatorfan

    gatorfan

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    Yes, it's pretty simple. First turn of the breaker which powers that light. If you don't have it clearly identified in the panel, you're going to have to go by trial and error and test the power (using a multimeter or test light) until you find the right one. Even if your breaker panel is well labeled, you should test the confirm that the power is off.

    Technically you could do this procedure by just turning off the switch. If you're comfortable working around electricity and the small chance of a shock, that's fine. But, if the original installer miswired the circuit (e.g. put the switch across neutral instead of hot), you could still have hot wires when you think it's off. The only way to know for sure is to turn off the breaker. That said, if you always treat wires like they may be hot, you'll be fine (and a 110V shock isn't that bad anyway IMHO).

    Then remove the fixture. In the junction/ceiling box above the fixture should be the wire nuts connecting the fixture leads to the supply wires. After you unscrew them, set the old fixture aside. Now is a good time to make sure the supply wires are right. Make sure all three supply wires (black, white, bare/green) are separated and turn the breaker back on. With the light switch turned on, test the voltage:
    • bare/green to black: 110-120V (or test light lit)
    • white to black: 110-120V (or test light lit)
    • bare/green to white: 0V (although this could be nonzero for various technical reasons, it should not be 110-120V).
    Repeat the test with the light switch off:
    • bare/green to black: 0V
    • white to black: 0V
    • bare/green to white: 0V
    If you don't get the correct results, post back here with what you saw. If it all tests out OK, turn the breaker back off and install your new fixture.

    Match the fixture wire colors to the supply wire colors and use the new wire nuts which were probably supplied with the fixture. You should not be able to see any bare conductor (except, obviously, if you have a bare ground wire in your supply) once you screw on the wire nut. It should just be finger tight, don't use pliers.

    Remount the fixture, turn on the breaker, and test to ensure the light works.

    Possibly. The most likely reason the incandescent bulbs fail quickly is the bulb is getting intermittent power due to a bad socket or loose connection. Turn off the switch, remove the bulb, confirm power is off, and bend the metal tab at the bottom of the socket out a bit. This will ensure you get a good contact with the bulb. When you reinstall the bulb, don't overtighten it. If you have the time, you could also check the wires as above and ensure the wire nuts are securely screwed on and making good contact between the three pairs of wires.

    Matt
     

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