pfo ballast question

[turbo21]

i have had my pfo dual 400w halide ballast for about 6 months ( bought it used) and have always noticed one side of the tank is significantly dimmer. it is not the bulbs, i had ushio bulbs and cheap ebay bulbs that gave the same effect, i have swapped the bubs back in forth, and it is always the same side of the ballast that is dimmer. am i destined to keep lower light corals on one side of the tank???


bob

[Roland Jacques]

That or get you ballast fixed

[turbo21]

what do you think has failed in the ballast?

can i replace it?

bob

[reefer0032]

You might want to open up the ballast and take a look at the capacitor, you might need to replace it. I had to replace one on my ballast, its not expensive and easy to replace.

[john rochon]

second the capacitor.

[turbo21]

thanks for the help guyz

just to verify, i am guessing i should check the output voltage of the cap, if it is off either way, replace it?

anyone have any cheap sites for caps?

bob

[PaulErik]

If the ballast you have is the standard magnetic PFO (ANSI M59) ballast (Model AQ2-400MH) and you have swapped lamps and ballast outputs around and have a light level difference this usually indicates one of the capacitors is failing/operating out of spec. Replacing the capacitor almost always fixes this problem. Replacement capacitors are usually cheap and I personally would recommend replacing both capacitors so both ballasts will be operating at peak performance. The replacement capacitors are available directly from PFO.

You can test the output voltage on a standard magnetic (probe start) ballast without a lamp operating. Usually the voltage (OCV – Open Circuit Voltage) will be off if the capacitor is failing. Another way is to test the capacitance of the capacitor.

The capacitor in a standard ballast is used along with the ballast to limit lamp current and for power factor correction. If the capacitor is off the lamp performance will be affected and so will the input power factor (which should be 90 percent or higher).

[turbo21]

thanks for the help,
talk about a great explanation, (that is what i love about rc)


i called pfo early this morning and left a message with the aquarium lighting dept., no one has called me back yet, does anyone have a better contact info there?

and if you know off the top of your head, how much do the caps cost?

bob

[PaulErik]

I would just try calling PFO Lighting during normal business hours 9 to 5 west coast time. The commercial division also sells the capacitors direct to the public.

The capacitor prices vary by brand and vender. They generally cost about 20 to 35 dollars for a capacitor for use with an ANSI M59 400-watt CWA (Constant Wattage Autotransformer) ballast.

[turbo21]

just got home and checked the output voltage

the good side reads 378 v

the bad side reads 364v


if i get a chance i will swap the caps between the ballasts

does this still sound like a cap issue. I found a hydroponic company locally that said they might have the caps i need for $5.00 each

bob

[PaulErik]

The voltage seems a little high. For an ANSI M59 ballast the Open Circuit Voltage (output voltage) should be within 250-360 Volts RMS AC. They should both read the same (within a few volts) so something doesn't seem right. A failing capacitor will cause a voltage difference. The best way to test would be to test the capacitance on the capacitor.

You can try swapping the capacitors and see which one is failing/operating out of spec. Make sure the replacement capacitor is the same value and temperature rated (or rated for a higher temperature).

[turbo21]

i swapped the caps yesterday, and the bad side worked perfectly,

i also talked with the lady at pfo, the replacement cap is $20 plus about $5.00 shipping, the reason they did not get back to me sooner, is she was in the warehouse working with the solaris line ( tried to get them to send me a demo, they did not go for it )

so thanks for all the help the replacement cap is on the way


bob