Low Output Ballasts?/Lighting 8/18/09
Hello everyone,
<Hi Mark>
I recently purchased a VHO ballast and VHO bulbs for a frag tank which I grow corals in to sell to the LFS to help finance my addiction to the hobby. The output of the new bulbs didn't appear any different than the standard 40 watt ones I was using before, so I checked the wattage with a meter I own. It is one of those that just plugs inline on the power cord.
It is dead on when I check my metal halides or T-5's on my main tank. It says the ballast is only putting out around 90 watts total (45 per bulb), far below the 220 advertised. It also tests for amperage and it is down considerably as well. They are definitely wired correctly as they were bought as a retro-fit kit from Hello Lights. They are clueless about what the problem could be and said if they light up there is nothing wrong with them. I disagree.
<What you are reading on the primary side of the ballast isn't indicative of the power the ballast is supplying to the lamp itself.
A magnetic ballast works something like an inductor, a coil of wire in a circuit which may be wound around a piece of metal (core). When current flows through the wire, it generates a magnetic field. Positioning the wire in concentric loops amplifies this field, and the ballast in tandem with a transformer controls the amount of current going to the lamps. Newer ballast designs such as ARO's, use advanced electronics to more precisely regulate the current flowing through the electrical circuit. Since they use a higher cycle rate, you don't generally notice a flicker or humming noise coming from an electronic ballast. Do not compare your current readings to MH and T-5 lighting. Different lamps require specialized ballasts designed to maintain the specific voltage and current levels needed for a particular lamp. If the ballast were defective, you would likely see flickering, or no light at all.>
Is it possible they are selling cheap ballasts not really putting out what they claim on the packaging?
<ARO is a reputable brand of ballast, the 220 watts/1.82 amps, strictly refers to the maximum power/current the ballast is capable of handling.>
I always had decent luck in the past with them so I'm not criticizing, just wondering if ballast brands could make that much of a difference.
<Unlikely.>
The brands and specs are as follows: ARO electronic ballasts model AS-220 and URI T-12 48" VHO bulbs (110 watt each). Have you heard anything negative about either of these brands?
<No.>
Any advice you can give to what may be the problem would be greatly appreciated. Your site is a huge benefit to the hobby.
<As above.>
Thanks again.
<You're welcome. James (Salty Dog)>
Mark