400w on a m80?

[manderx]

i'm probably going to regret posting this, for making me look stupid. but since many 250w bulbs seem to run at 350-375w on a m80 ballast, what would happen if you tried running a 400w on it? i'm just wondering what a slightly under-driven 400w 10K XM would look like. i'm guessing that it probably won't fire, or if it does, not reliably and every time. but if it does run, seems like a slightly bluer w/less blaring rage than the 400w 10K XM run at spec would be a really sweet look.

[DocG]

Sanjay's lighting page (http://www.reeflightinginfo.arvixe.com/)
Go to the performance data section and if you search by ballast you will find that the PFO HQI ballast will use between 438W and 538W depending on the lamp. For example the 10,000K XM will run at 478W.

[manderx]

yeah. the HQI version of any wattage class does overdrive lamps, that's kinda my point. if there's enough latitude to overdrive bulbs at such a wide range, then what would happen if we dropped it down just a little and under-drove it on a 250hqi, which is on the high end of the next wattage class down from 400 and able to porivide at least 375 watts. or is there some other variable going on with ballasts other than the amount of watts they let out into the bulb? like does 400 have a bigger cap to get it fired-up so it wouldn't be able to fire at all on a 250hqi?

what i'm really looking for is the xm15K that we were hoping for, something similar to the par of a 10K with some of the blue of the 20K. not less par than the 20k that we are seeing. from seeing how other bulbs run on different ballasts/wattages (for example i recently saw an ab10K on electronic,m58, and m80), it just seems that if it's really white and bright at ~400 watts, then it *should* be a little dimmer (which is ok since the 400w 10K is too bright for my tank) and a little bluer at 375 watts. exactly what i'd want out of the 250w 15K.

[AQUAN8TOR]

Hey there. I guess you could just use a blueline 400w ballast, which uses about the same wattage, and fires the bulbs that much dimmer!!! LOL. I'm not a big fan of the bluelines. They run dim on everything.

I know this doesn't help I just couldn't help posting.

[manderx]

heh, i like that kind of thinking....

[DocG]

Sorry manderx,

I completely misunderstood your post.

I am pretty sure that you cannot run a 400W bulb on a 250W HQI ballast. I have no idea why but you are probably right about the capacitor.