HID ballast output

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nizak

Senior Member
Can someone give me the output voltage range for a 250W metal halide ballast. I realize starting voltage will probably be considerably higher than operating voltage. Thanks.
 

Jraef

Moderator, OTD
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Electrical Engineer
Can someone give me the output voltage range for a 250W metal halide ballast. I realize starting voltage will probably be considerably higher than operating voltage. Thanks.

What is your reason for asking? It's not really a simplistic issue.

The "Open Circuit" votlage coming from the ballast is usually somewhere around 350-400V, although the lamp voltage is usually around 135V. When the lamp is in the circuit, the lamp voltage is what you would measure on the output of the ballast though, the open circuit voltage is only relative to what you might read on a meter in that you can't really use it at that level, it drops as soon as you apply a load to it.

But "considerably higher" for the starting votlage? I'll say!
Strike voltage is 3-5kV, then if you have a "warm restrike" type (rare), it can be 25-20kV!
 

nizak

Senior Member
I have a customer who called and said his maintenance guy changed lamps and photo cells in some 250W MH fixtures because they quit working.He probably spent a lot of $$$$ and wasted a lot of time by simply assuming that is all that could be wrong with them. I told the guy on the phone that it's possibly ballast or capacitor problems instead. He says it can't be because the fixtures are only 3 years old. I replied that the age does not necessarily mean they can't go bad. I just wanted to get a starting point as to what the output should be.
 

480sparky

Senior Member
Location
Iowegia
HIDopencircuitvoltages.jpg
 
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