175w MH ballast only pulling 120w?

[Anonymous]

Ok something is wrong with my ballast. Now I have an older custom sealife, magnetic ballast (dual) it's really looking funky from rust over the ages, however today when I was trying to gauge how much power my tanks are drawing I came to a shocking revelation.

The ballast is only drawing 120 watts! I used a kill-o-watt meter, and sure enough it started out rather low 50watts, figure it's warming up,etc, however after leaving it sit for an hour or so, I looked at the KaW meter and it showed 120watts across it. Tested it on the other ballast, also 175watts, and the same thing!

Now here's a question, since I doubt an old magnetic ballast is only pulling 70% of what it's rated at, could there be something wrong with the ballast? My bulbs fire just fine on them. And even though I really hate to say this (because eye balling how bright they are really isn't very scientific) but... they look pretty damn bright as it is.

Other option, some how my KaW meter is being fooled somehow by the ballast ?? Perhaps the magnetic ballast has some "back flow" (for lack of a better term) which is fooling the electronics?

Anyways, just wanted to know what others thought or if they heard or experienced this as well. I got a dual 150w setup that I was going to replace just to save power but jesus that one pulls 160w per ballast!

 

[Anonymous]

I have NO idea, but Louey would be the person to know or have the closest thing to a final answer on this.

Honestly though, whatchoo complainin' fer? If the lights are putting out the proper lumens and spectrum, yeah? Can't measure spectrum in any handy way I know of, but lumens are easy with a meter.

 

[Anonymous]

I have NO idea, but Louey would be the person to know or have the closest thing to a final answer on this.

Honestly though, whatchoo complainin' fer? If the lights are putting out the proper lumens and spectrum, yeah? Can't measure spectrum in any handy way I know of, but lumens are easy with a meter.

Well I'm not exactly complaining about my magical 175W ballasts using less energy, however if it's because there's something wrong, then I'd like to stop using a faulty piece of electrical equipment around saltwater

I honestly don't know if they're putting off the correct lumen/spectrum, yeah the bulbs look bright enough that it hurts, but that's hardly scientific, not to mention I don't have a reference point to measure against even if I did have a lumen meter.

 

[blackcloudmedia]

lol only YOU would have the spare time to measure how many watts your pulling....Im lucky enough to have time to clean the tank hehe. jk :wink:

 

[Anonymous]

Obviously, the bulb is pretty forgiving when it come to amp/volt, and same as watt. Watt and voltage is a tricky thing to measure in AC current. You should know that. Besides, with the ballast, it is impossible to get it to what it need to do if there is no room for "error." Take a look at the ANSI specification, and you maybe able to see that to be call a M-58 certified ballast (or whatever designation it is called), there is some room to play around. The XXX Watt ballast is just for non-engineer to find the right ballast for the bulb, etc..

Now, that is just for the output side of the ballast. For the input, there is obviously some limitation as to how low the parameter can get. But as to the current draw, different ballast type have different value.

Now, that just the input and output. As mentioned before, current and voltage is a tricky thing to deal with in AC. On the instrumentation side, do you know exactly how the kill-a-watt does to compute the wattage? Does it use some kind of RMS aglorithm, and how fast is the sampling rate?

 

[Anonymous]

Can't say exactly how it works, nor the sampling rate, however I get what you're aiming at, maybe with the magnetic ballast operating at 60Hz, I'm somehow getting a low reading because it's not measuring all the peaks.

 

[trido]

If you look at Sanjays website regarding ballast performance data, there is alot of wattage output variance depending on the bulbs. For exapmple, with the icecap electronic 250 the wattage output ranges from as low as 196 to as high as 256. Im not suprised your ballast is only pushing 120 watts. It could just be the bulb.

Here you go.
http://www.reeflightinginfo.arvixe.com/ ... allast.php

 

[Anonymous]

It is probably a function of both the bulb and ballast, with variance among the bulb the greatest. It is not easy to make identical bulb enen with the mechanized assembler they use in factory.