View Full Version : Choosing A Ballast
Simply question really, how do you compare different makes? I've just about managed to work out the difference between magnetic and electronic ballasts but how do you choose between makes within these types?
Can you even make a meaningful choice on a ballast on its own without also reflecting the make of lamp you are likely to be running on it? (I've picked up the impression that an individual ballast can run some lamps better than others?)
Suspect the answers are far from straightforward and grateful for any corrections and explanations from members/sponsors.
:thanx:
Keith
CoralCulture
23-09-05, 09:37
Keith, its a real can of worms in my opinion. Lots of tests with ballasts and lamps have been done, and as you suggest the results vary dramatically - these tests where in the US, where the voltage is different and most of the ballasts and lamps are not available here anyway - so its fairly meaningless, apart from to highlight the difference that can be experienced from one ballast/lamp to another.
Of course... this is all assuming you are going to scrutinise the lighting to that level!
We have sold plently of setups containing a mixture of ballasts but using Coralvue lamps and most have been happy - of course some only wanted Xm, Arcadia, some only Blv etc etc....
In my opinion there is no hard and fast rules. I dont envy anyone trying to make a choice! All we can do to help is offer a "trial" on the lamps to help you along (assuming all the kit is purchased from us of course!)
Glenn@home
23-09-05, 11:51
It should also be remebered that what you end up with in terms of illumination over your tank is heaviliy influenced by reflector design too and different reflectors will perform differently with different lamps unless their geometries are exactly the same and somehow I doubt this is the case.
The third element inthe equation just increase the amount of choice/difficulty without there being any 'true' answers.
Whether the change between two lamps of similar desing in a single reflector makes a huge difference is difficult to say without doing some tests. As I recall Andy Hipkiss and Matt Beaman did some comparitive tests with reflectors but i cannot recall exactyl what they did in respect of lamps.
One of the conclusions is that the PAR is not evenyl distributed as one would think and there were peaks and troughs in the distribution.
If you havent seen it, it may be interesting at least to get an idea of the difficuties and perhaps help you make a pragmatic judgement without worrying to much about the details.
HTH
Glenn
I assume you have checked Sanjay Joshi`s lighting website. Loads of info and comparisons of ballasts on there.
Im in the process of choosing a 400w lamp, ballast and reflector for my next setup and its giving me a headache :wacko:
Ive read through Sanjay Joshi`s website and test pages and it just made the situation worse. 1 thing im certain on so far is the reflector which will be a Lumenarc III. Not because its probably the best reflector on the market but because of my tank shape :lol: But picking a ballast and lamp is not an easy choice. I think im best just sticking some names in a bag and pulling them out :lol:
Lumenarc IIIs....lovely !
On the ballasts. I think that some US reefers take this to the levels of fetishism. As Nick says, they have more variety over their, so that means a little more care is necessary, but some of the stuff I've read seems outlandish.
Anyway, short (?) answer is:-
There are two types of metal halide lamp.....most (possibly all) designed for Europe are pulse starts. The ballast uses an ignoitor to generate an initial high voltage pulse to kick-start the lamp, and then settles at a lower level. Most US lamps use probe starts. The ballast doesn't provide any pulse, the lamp itself contains that mechanism.
A probe ballast will not light a pulse lamp. A pulse ballast will light a probe lamp, but some people say that life may be affected.
So you have two types of ballast...pulse start and probe start. Plus an extra posssibility, which is electronic, which will automatically drive either lamp and is less wasteful, meaning that it is cheaper to run (but is also more expensive to buy and more prone to die).
I think that all DE lamps are pulse start, and makers usually recommend a slightly different ballast for these, although the difference is minor.
Finally, the Iwasaki 6,500 lamps use mercury vapour technology, so use a different ballast. Be warned, but unless you are using these lamps, don't worry about it.
Some ballasts apparently generate more light than others. I find this hard to believe, in many cases it turns out that the "good" ballasts simply draw more power and use more power to drive the lamp. Which burns brighter. Big deal.
Then some claim a better colour under different ballasts. Well, the wavelengths which a lamp emits are fixed by the chemicals it contains, and no amount of ballast technology can change this. But probably increasing the power would tend to cause more emmission in the blue end of the spectrum.
Every maker will tell you that their ballast is best...
Finally, most lamp and ballast makers if they distribute in the US will categorise their products by an ANSI number, so if you match the ANSI number for the lamp and ballast, you have a pair.
kim
Originally posted by nickjc@Sep 23 2005, 08:37
Keith, its a real can of worms in my opinion. Lots of tests with ballasts and lamps have been done, and as you suggest the results vary dramatically - these tests where in the US, where the voltage is different and most of the ballasts and lamps are not available here anyway - so its fairly meaningless, apart from to highlight the difference that can be experienced from one ballast/lamp to another.
Of course... this is all assuming you are going to scrutinise the lighting to that level!
We have sold plently of setups containing a mixture of ballasts but using Coralvue lamps and most have been happy - of course some only wanted Xm, Arcadia, some only Blv etc etc....
In my opinion there is no hard and fast rules. I dont envy anyone trying to make a choice! All we can do to help is offer a "trial" on the lamps to help you along (assuming all the kit is purchased from us of course!)
Thanks for this Nick - it was looking at the IceCap and Coralvue ballasts on your site that prompted my post.
Given the lamps I'd hope to run I think I'd opt for the Coralvue as, according to Sanjay's tests (thanks for reminding me of these Danny - couldn't remember the guys name), it seems to push out 10-20% more PAR out of them than the IceCap (though whether this is still the case with the 240V types is anyones guess...).
By the way, do you think you might stock the XM 15000k 400w at some point?
Keith
Originally posted by kim@Sep 23 2005, 13:34
Some ballasts apparently generate more light than others. I find this hard to believe, in many cases it turns out that the "good" ballasts simply draw more power and use more power to drive the lamp. Which burns brighter. Big deal.
Then some claim a better colour under different ballasts. Well, the wavelengths which a lamp emits are fixed by the chemicals it contains, and no amount of ballast technology can change this. But probably increasing the power would tend to cause more emmission in the blue end of the spectrum.
Every maker will tell you that their ballast is best...
Interesting Kim,
Sanjay's results do show that some ballasts are delivering more PAR through using more power like you say. Not a bad thing or inconsequential thing I would have thought provided it was doing this efficiently (and Sanjay's tests seem to show that there is some variation between ballasts here)?
Your post has raised another question in my mind though. Might driving a lamp to deliver that additional output come at a cost in terms of lamp aging/shifting? Don't suppose you or anyone else is aware of any research on that?
Keith
Glenn@home
23-09-05, 21:19
Keith
Bearing in mind im going to face a similar question,m hopefullly in the not to distant future i think you should get several different ballast/lamps/reflectors and swap them around and see what works best. :lol: :lol:
Originally posted by Glenn@home@Sep 23 2005, 20:19
Keith
Bearing in mind im going to face a similar question,m hopefullly in the not to distant future i think you should get several different ballast/lamps/reflectors and swap them around and see what works best. :lol: :lol:
Hmmm.... I think you should sponsor me Glenn :D
The thing I'm most certain about at the moment is the reflector - Luminarc III. I want to see how this looks and if its as good as they say (and doesn't look too industrial for my lounge) I'll switch the other two lights over as well.
Keith
I’ve just made a DIY copy of the Luminarc III and even my somewhat less than perfect copy is much brighter than any other reflector that I’ve tried.
have a look at this link to one of the major ballast manufacturers
www.vossloh-schwabe.com
if you follow the discharge lamps links it will show you a chart of what ballasts to use for which make of lamp and also the size pfc capacitor and even how to wire it up.
steve
CoralCulture
02-10-05, 21:55
By the way, do you think you might stock the XM 15000k 400w at some point?
Keith, they have just arrived :thumbsup:
Keith,
According to sanjays site the 15K XM isn`t patch on the 10 K and only offers roughly the same PAR as the 20K. :(
WRT ballasts looking at the power consumed you can save over 20% in electricity cost by using an electronic ballast. I know some of the magnetic ones seem to give fractionally more PAR but if this is at the expense of lamp life and greater electric bills (and more heat) then the electronic ones look like a good option.
Danny
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