Need help with damaged ballast circuit

Discussion in 'General Electronics Chat' started by sophiaharcourt, Nov 7, 2006.

  1. sophiaharcourt

    Thread Starter New Member

    Nov 7, 2006
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    0
    Hi everyone...

    First off, I have no experience whatsoever in circuitry except I know what a capacitor and a resistor are. I can do a little household wiring, but that's the extent of my electrical knowledge, so please, if you respond, please make sure that a beginner could understand!

    I have a ballast for a large security light which floods light into the area behind my business (fenced-in parking area). The other day, the light stopped working. I was not around to determine if there was a loud bang or light, etc. I tried using a different bulb, but to no avail.

    Well, I like working on projects myself, and this light isn't an emergency, so instead of getting a new one, I decided to take the ballast apart.

    Here is what I have, and what I saw. If it's not enough, I can take pictures which might help, just let me know:

    It is a 600 watt ballast, and it's supposedly an 'electronic' ballast, which I guess is a new design.

    I took the cover off and unscrewed the circuit board, which has lots of things ... I kept looking around the entire board for any sign of damage... I finally found something! There is a small space on the circuit board with a little bit of grey ash looking stuff, like something blew out! And if you look closely, there are two wires sticking out of the circuit board, but they connect to nothing. It looks like the two wires that come out of the board and connect to something like a resistor or capacitor, except in this case, there is nothing there. I looked around the case, and could not find whatever it was that blew up! It must have disintegrated. The only clue as to what it was is a 3 letter code printed on the circuit board: BXS.

    I don't know what a BXS is! I can tell you some more details. I followed the three input wires (white, black and green) and they enter the board, and following their path (I hope I followed the path correctly) they first enter a yellow box. There is a large yellow capacitor soldered in front of the box, but the circuit path that the black wire follows also connects to this yellow box. The markings on the box are:
    1uF K 275V ~
    MKP X2 40/85/21
    EN132400 250V~

    Following the path the black wire takes, we then get to the infamous 'BXS' which has been blown apart! After the BXS, the path goes through 2 big capacitors and then it goes on through a lot of circuits that are hard to follow.

    Can someone please tell me what a BXS is, what could have caused the BXS to blow up, has it damaged other parts and where can I get a replacement BXS?

    Sorry for the long post!

    Thank you.
     
  2. sophiaharcourt

    Thread Starter New Member

    Nov 7, 2006
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    Here is a picture I took.. You can see the BXS near the middle of the photo.
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    Whatever it was, it's gone now. It might have been some kind of surge arrestor that got zapped by a big voltage spike. Your yellow device is a 1 microfarad 275 volt capacitor.

    Without another ballast to figure out what the vaporized device was, there is really no way to tell. As other devices might have suffered, you're probably better off getting a replacement ballast. If you're brave, you can open up the replacement and see what blew up in the original.
     
  4. sophiaharcourt

    Thread Starter New Member

    Nov 7, 2006
    4
    0
    Oh, I thought 'BXS' was code for something like a capacitor or resistor! I saw that the capacitors are numbered C1, C2, etc...

    Bummer... I wonder if I get can the information from the manufacturer...guess I can try that.
     
  5. Gadget

    Distinguished Member

    Jan 10, 2006
    613
    0
    Looks like your BXS is in the supply to the rectifier/filter, and thus is probably a protection device (possibly a fusible resistor or PC mounted fuse). Being an electronic ballast, it follows there will be some sort of switch mode stage following, which in all likelyhood will be shorted (thus causing the vapourisation of your BSX). Unless you are familiar with this sort of thing, AND can get EXACT replacement components, I would suggest taking the cheapest option and following previous advice by replacing the ballast.
     
  6. sophiaharcourt

    Thread Starter New Member

    Nov 7, 2006
    4
    0
    Thanks for the reply..

    You say that the component probably blew up due to a short somewhere else.. is it possible that a power surge through the power line cause this instead?
     
  7. Gadget

    Distinguished Member

    Jan 10, 2006
    613
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    There is every possibility that a power surge may have caused it, but by the way the component BXS has vapourised, it's a good bet that the first thing to die was actually the primary/output device in the switch mode supply.
     
  8. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    It also looks as if the trace has been severly damaged or opened. I'd replace it and while getting the ballast get a wired in surge arrestor.
     
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