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  1. #1
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    MH light problem

    My MH light is behaving badly. Not sure if it is the bulb or the ballast. It runs well for an hour or so, then flickers and the ballast makes a clicking noise. It just shut off completely. Any ideas? Ballast or bulb? It's a 175W MH driven by a 175W ballast.

    thanks ....

  2. #2
    Senior Member
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    how about your timer?? is it an ourdoor black colored intermatic digital?? what ballast do you have? how old is the lamp?? chances are, its the timer believe it or not, I just went thru the same thing. I unplugged the timer and retry'd and it worked okay for a few days but then back to the same thing. New timer,no problems. You have a standard ballast right? try using no timer once the lamp has cooled,

  3. #3
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    thanks - just tried that - same deal, therfore not a timer problem. Seems a regular pattern - good for 15 minutes, then flicker for 2 minutes, then off. Ballast is warm but not overheating. Bulb is approx 1 month old.

  4. #4
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    My bet would be on the ballast if the ballast is the proper match to the lamp.

    The clicking sound you hear maybe the ballast trying to re-fire the lamp.
    Is it flicker,then lamp goes out then ballast clicking?

    Tough call though, could still be the lamp.

    Lou

  5. #5
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    Do you have only 1 set of bulb/ballast? If you have more than one, try switching the bulb to the other ballast and so on to see which is defective.

  6. #6
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    What type of ballast and what type of bulb is it? My friend has a similar problem with one of his setups. Turned out to be a bad ballast.

  7. #7
    Senior Member Deafboy's Avatar
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    Re: MH light problem

    If you have a coil/capacitor ballast like my Hamilton technology, you can check with a multimeter to see if it is works properly.

    - Remove the bulb and mesure the AC voltage at the socket terminals. It should be between 285 and 320 volts. Any lower and the bulb won't fire. Some bulbs don't fire well even at 300 volts.

    - Measure the short circuit current of the ballast by using the highest current position on the ammeter function of the multimeter (usually 20 A). You should get around 1,5 to 1,9 A (AC).

    Since the bulbs fires when cold then I would think that the either the bulb or capacitor is failing.

    BTW, a bulb has to cool down before attempting to restart. This is because the gas pressure of HID bulb is very high when operating (around 75 atmospheres!). The voltage needed to fire it would be much greater than supplied by the ballast.

    Michel
    20 g reef, 72 g reef

  8. #8
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    we have to know the lamp and ballast because some lamps are probe start and others are pulse. but you say it worked for a month?? if its a standard ballast chances are its NOT that as those ballasts are really hard to kill but ya never know.I'd say lamp if it was working for 4 weeks.

  9. #9
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    Thanks for all the tips folks. The mystery is now solved - borrowed a friend's MH bulb and presto - problem solved. Bad bulb. Bummer.

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