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Slick Fork
04-18-2009, 04:46 AM
Hi there,

I was just wondering what the normal power draw should be on a magnetic ballast 250 watt DE bulb should be? I noticed tonight that one of the bulbs had blown a fuse on my profilux power bar so I hooked it up to a watt meter and found that it's drawing a consistent 420-430 watts after the start up phase. This seemed really high to me so I checked the other one and it's reading the same thing.

They're both factory magnetic ballasts on a geisseman fixture and the fact that they are both reading identical draws makes me want to rule out a faulty ballast (Pretty slim odds that both are pooched but you never know).

So, are these normal draws? I had been expecting in the neighbourhood of 300-350 but maybe I just pulled that number out of my butt.

Thanks

mark
04-18-2009, 05:07 AM
Been a while since I checked but believe my 250W PFO was around 300W

brickwood
04-18-2009, 05:10 AM
Measure how many amps they are drawing.

Jack
04-18-2009, 05:20 AM
IIRC, 5.5 amps.

Slick Fork
04-18-2009, 05:27 AM
Peak amps was 7.1, once it settled down 5 and change seems to be the number I'm remembering

StirCrazy
04-18-2009, 05:27 AM
sounds a tiny bit high but now unreasonable, usaly they are around 400ish

Steve

Jack
04-18-2009, 05:30 AM
www.manhattanreefs.com/lighting

fkshiu
04-18-2009, 06:16 AM
That's a bit high for an HQI ballast, but not ridiculous. Is it more than a few years old?

If you want to save some electricity at the cost of some PAR go with electronic ballasts which will draw as advertised. Electronics are also smaller, lighter, run cooler and silent but they do cost more.

Bryan
04-18-2009, 09:00 AM
http://www.fortunecity.com/meltingpot/cambie/38/id53.htm

What does the capacitor do in the ballast circuit?
The capacitor controls the power. Making the ballast more efficient (HPF).


How do you know when the capacitor has gone bad?

The lamp will not normally work if the ballast circuit is a CW or CWA.
Testing is the only way to know when the capacitor has gone bad on HX-HPF and R ballast circuits. On HX-HPF and R the amp draw will almost double when the capacitor fails.

Slick Fork
04-18-2009, 04:46 PM
Bryan: The site you linked to prompts a warning message that it has been flagged as an attack site by google/firefox

Fkshiu: The current ballasts are at least 3 or 4 years old but I am not sure of the exact age since I bought the fixture used.

I have considered E-ballasts and done some looking at Sanjay's site, I am unsure how much a drop in Par will affect my tank, all of my sps' are up in the top 8" of water and I have no plans to populate the bottom with sps.

My other concern with E-Ballasts would be interference, I seem to remember reading somewhere that electro magnetic interference has been an issue with these, the ballasts would be about 4 feet from my profilux controller and 5 feet from the lcd tv/stereo/bluray set up. Any thoughts?

Mrfish55
04-18-2009, 05:01 PM
I just upgraded to the 400w Vertex electronic ballasts and am happy so far, no noticible interference with anything. I plugged it into my fancy new electronic energy meter and I am only drawing 10 amps running 3 ballasts, estimated consumption is $0.64 per 8hr day which is quite a bit less than the 250w tar ballasts I was running. By my calculations the electronics will pay for themselves within 1 year of operation.

spreerider
04-18-2009, 05:50 PM
Electronic ballasts should have less interference as they operate on higher frequencys in order to be more efficient, mag ballasts create way larger mag fields that can affect other electronics, but they have to be fairly close.

You would know if the capacitor went, the circuit would not work anymore, and it will probably smell horrible,
I work on MH lights at work, we make ones for fish farms that go underwater with remote ballasts, sometimes the caps go and fill the enclosure with the capacitor material and it smells so bad it hurts the eyes and lungs.
The ballasts we use are isolated secondary so slightly less efficient but we draw 500W on a 400W Fixture and 1200W on a 1000W fixture. They are coil and core non autotransformer type.

Slick Fork
04-18-2009, 06:16 PM
The bulb fires right up, the fuse that was blown was in the powerbar. Thanks for the info on the 400 watt vertex Mrfish55, for me though upgrading the wattage and bulb type like would mean a brand new fixture.... tempting though I am very interested to hear from people who upgraded their 250w HQI ballasts to 250w E-ballasts as well.