# mh in hps ballast works, hps in hps ballast don't work



## stonegroove (Feb 12, 2009)

i've got a hps ballast and i put a mh bulb in it for veg, now its time to go back to an hps bulb but the ballast wont light it, its weird, i thought the bulb was just bust but i've tried 3 bulbs now, its only a magnetic ballast but its woked fine in the past. any ideas anyone?


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## The Hemp Goddess (Feb 12, 2009)

Are you sure that it is a HPS ballast?  Unless you have a digital ballast or a conversion bulb,the MH should not have lit--MH and HPS bulbs are not interchangeable.


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## stonegroove (Feb 12, 2009)

yep deffo a hps ballast, sez it on its top and it came with a hps bulb, apparently you can put a mh in a hps ballast but not a hps in a mh ballast


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## kalikisu (Feb 12, 2009)

so now the ballast wont light the original hps?


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## blancolighter (Feb 12, 2009)

Meybe ya broke it with MH??


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## stonegroove (Feb 14, 2009)

yeah the original hps wont light but the mh still works i'll just continue to flower under mh, i've read that it'll make them ripen faster but with lower yield, i'd still like to fix the problem somehow though


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## Lemmongrass (Feb 14, 2009)

theres no way dude. whats your bulb look like? my system is a mh ballast and a conversion bulb. it was given to me as an hps, since it had the conversion bulb in it, it wasnt until i wondered why the big box of random replacement bulbs was mh and why the inside of my bulb looked funny.


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## JBonez (Feb 14, 2009)

what kind of ballast is it, ill tell you what your doing wrong if you give me specifics mate.


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## clanchattan (Feb 15, 2009)

the "starter" in your ballast is bad. we test hps ballasts at work with metal halide lamps.

hps ballasts have 3 parts as a rule:

1. coil and core - the transformer
2. capacitor - supplies a consistant voltage to the lamp so light levels don't
                   fluctuate
3. starter - supplies a arc to the center tube to light the hps lamp

halides have only the core and coil and the capicitor.

if a mh lamp lights in a hps system the starter is bad. if it does not light then you have a bad capacitor or the ballast is shot.


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## bombbudpuffa (Feb 15, 2009)

My HPS fires up my MH bulb and my HPS still works. Running an MH with a HPS ballasts just shortens the life of your MH lamp. Probably from being double ignited.


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## Johnnyrotten123 (Feb 15, 2009)

ClamC, Stonegroove i'm sure is very grateful for your diagnosis even though it means he's MH the rest of the wat or replacing the starter. My question, i replace alotta starters that fire flouro. where i work(slot machines). I just bought a 400w hps, how often/durable r the starters that 'fire" these lamps? I'll  not be running the wrong bulb but just curious if this is a typical problem as it is with flouro-ty in advance


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## Leafs.Rule.75 (Feb 16, 2009)

bombbudpuffa said:
			
		

> My HPS fires up my MH bulb and my HPS still works. Running an MH with a HPS ballasts just shortens the life of your MH lamp. Probably from being double ignited.


yep thats all i heard it does too, a good friend mine owns store and he will tell his customers they can just use reg mh bulb in a hps it just shortens the bulb life


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## clanchattan (Feb 16, 2009)

hps startes are the most common part to fail in c&c (core and coil) ballast units. if you don't turn the lights on and off repeatedly, the starter will take a while to go bad. they are designed to provide an igniting arc to the sodium tube, the small center tube, in a hps lamp and have a determinenate life span. the more often the lamps are lit, the sooner the starter goes bad but anything under say, 20,000 hours would be considered abnormally short. Unless you are running the wrong lamp. if you need to run a mh in an hps set up go for a pulse start mh at the very least, or pay the money for a conversion lamp.


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