OK, it seems that dimmable electronic ballasts come in two basic "flavors". There's the ones that dim to 50, 75 &100% (plus Extra Lumens). Then there is the other kind - the ones that dim to specific wattages: for example 150 watt, 250 watt and 400 watt. I'm not at all interested in the first kind (the ones that dim by a relative per centage), I just feel that's all kinds of wrong for the spectrum you might get from an arc tube that's only getting partial power. So, my actual question is this: does a "400 Watt" dimmable ballast, that is dimmed to 250 watts allow the user to replace the 400 watt bulb with a 250 watt bulb? The proper bulb for the proper wattage - that's what I'm looking for!. All the information I can find is from advertising - so the wording is very vague, not helpful at all. So, if anyone has one of these "Watt Specific" ballasts and has actually read the brochure; I woild appreciate knowing if I can swap out the bulbs as mentioned.
Electronic Ballast ???
- Thread starter T.H.Cammo
- Start date
V256.420
Well-Known Member
You really need to match the ballast watts with the bulb watts for electronic ballasts. Also, your thinking is a bit off with the %%% thing and the "precise" watt thing.
It doesn't matter. You are still dimming the bulb. The thing you want to know is if you could run a lower wattage bulb in a higher ballast. You CAN, but IMO it's not safe. Just in case if you get a power surge and it blows your bulb.
Stay safe, better than sorry
It doesn't matter. You are still dimming the bulb. The thing you want to know is if you could run a lower wattage bulb in a higher ballast. You CAN, but IMO it's not safe. Just in case if you get a power surge and it blows your bulb.
Stay safe, better than sorry
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Thanks for the reply, Dude! But I'm not talking about LED's, I'm talking about HID ballasts and from what I understand: underpowering HID bulbs will result in severe spectrum changes - sure the bulbs will light up but the spectrum will be way off.
PJ Diaz
Well-Known Member
Sorry, my bad that was a typo. FIFY. I meant HPS not LED. Yes, the spectrum does change, but honestly the HPS spectrum is already not the best for plants, so who really cares?
It sounds like you're saying you can swap the bulbs out - but that might not be such a good idea. My question is this - is that what the brochure says or is that just your .02 cents worth?You really need to match the ballast watts with the bulb watts for electronic ballasts. Also, your thinking is a bit off with the %%% thing and the "precise" watt thing.
It doesn't matter. You are still dimming the bulb. The thing you want to know is if you could run a lower wattage bulb in a higher ballast. You CAN, but IMO it's not safe. Just in case if you get a power surge and it blows your bulb.
Stay safe, better than sorry
PJ Diaz
Well-Known Member
This is taken from Hortilux's page. You see the parts of the spectrum which are mostly diminished are the greens we don't really even need for photosynthesis, so there's an argument to be made that dimming could improve spectrum.
PJ Diaz
Well-Known Member
My ballast didn't come with a brochure, did yours?
I guess my 2 cents worth (although you only asked for 1/10 of 2 cents), is steeped in experience having done it multiple times in the past? It hasn't always been international either. A year or so ago I went to replace a 600watt lamp in a 600watt ballast that was old, and when I took it out I come to discover that I had accidently put in a 400watt lamp for a few weeks. Oops. I guess if dimming makes the spectrum worse, then what I did made the spectrum better?
With many dimmable ballasts they are set for 50%, 75% or no dimming. With a 600watt ballast dimmed to 50%, what lamp would you put in there? Last I checked they don't make 300watt HPS lamps.
So, does the brochure say that it's OK to switch out the bulbs for lower wattage when the ballast is "dimmed"? Or are you supposed to keep the higher wattage bulb in place?
Renfro
Well-Known Member
Generally they recommend using the larger size bulb when dimming. That said I have done both. I have ran 1kW ballasts at 60% power with a 600 watt bulb and I have done it with 1000 watt bulbs. Both worked.
You don't want to run a bulb lower than 60% of it's design watts as this causes an unstable arc and shortens bulb life.
osowhom
Well-Known Member
buy the 600 watt not 400 trust me you will wish you did go with the vivosun dual bulb and yes you can run it at 400 no problem 250 is not enough to flower
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Yeah - I'm hep to the "low power thing". My plan is to use low wattage x 3: two Metal Halide and one High Pressure Sodium in Veg - then reverse to two High Pressure Sodiun and one Metal Halide for Flower. That way I get the best from both spectrums