Can you run 315w LEC/CMH bulb off a 400w HPS ballast?

gregulator83

New Member
Hi Guys,

Long time viewer first time poster.

I want to upgrade to one of these new LEC lights but the expense is astronomical. I'm assuming the 400w hps ballast will be too much power for a 315w bulb and just blow it immediately.

Has anyone retrofit one if these LEC/CMH to their old hps ballast and reflector ? I know they sell retro fit kits online but for the cost I may as well just buy a whole new lighting setup.

Thoughts ?
 
short answer.
Yes, you can. However, you'll be overdriving the lamp by ~85W or so. The LEC/CMH lights use a standard Magnetic ballast, like the ones that used to be used on MH/HPS systems. The only difference is that they are current limited for a maximum output of 3.15A @ 100V.
One could parallel 2 x 160W MH ballasts to make the setup work effectively.

Dirty secret is that HPS is actually a kind of LEC/CMH lamp. The arc chamber for HPS is Sintered alumina (Aluminum Oxide), which is identical to what is in a LEC/CMH lamp. Only difference is in the arc chamber filling. (mostly Hg and a few quench gases)
 
I thought my 2 SS 315 lec lights had a 50/60 Hz low frequency, square wave, highly efficient electronic ballast rated for 50,000 hour ballast life. At least that's what i read...

i think your right in a way. some bulbs don't work on digital ballasts but if it works on a digital ballast its then backwards compatible to a magnetic.

Please correct me if i'm wrong.
 
Thanks Canresearcher,

I done some research since and it looks like it can be done. Im not to worried about the wattage difference as the circuit should take what the circuit wants and as long as i don't over rate the ballast i.e pull more current thru than design of 400w or 4.0A @ 100v (V=IxR) so 3.15A @ 100V should be fine.

Im gonna grab a bulb and a converter plug and give it a go.

Ill post results in case your interested if it works.

If i don't repost i've burnt the house down ;)
 
Not exactly.. Digital ballasts use inverter technology ( same transistors to what is in your car DC-AC inverter ) to get more out of the bulb (higher efficiency.) It also means you can vary the output current thereby using different Wattage bulbs. It switches via pulsed DC (Square wave) at 50-60hz or higher frequencies (100s of Khz). You can use any standard HID style bulb on an electronic ballast. The bulb doesn't care. What will ruin a bulb is continuous hot striking /starting. Eventually this can damage the cathode/anode and degrade the bulbs performance.

Most commercial LEC/CMH that I've seen use old style magnetic ballasts (dime a dozen $80-$100 or less Home depot..etc). instead They're being way overpriced on purpose by companies wanting a piece of the POT pie. There is a great deal of snake oil being used by these companies to market these "LEC/CMH" only ballasts. CMH/LEC bulbs are interchangeable with standard MH ballasts. The only difference is that they use alumina ceramic arc chambers instead of quartz arc chambered ones.

@gregulator83 ---> you'll have a good result. :thumb:
 
Hi Guys

Thanks for all the input it has been a great help spurring on my research

From what i have found there are many many many CMH products available for my purpose unfortunately they are not available in my part of the world currently. link attached

MASTER CosmoWhite CPO-TT Xtra 315W/942 E40 MASTER CosmoWhite CPO-TT Xtra - Philips Lighting

i have a HPS only ballast and from what i can see this product is designed to retro fit to a HPS only ballast.

but not to fret i'm going to pick up a cheap MH ballast and give the CMH a go this run.

With any luck ill do a journal of my DWCR 315w CMH/LEC SCROG Trainwreck

Wish me luck boys :)

Special thanks to canresearcher <3
 
The bulb in the link is a slightly different one than the with the posts. 94V at 3.35A input instead of the 100V at 3.15A for the other bulb.
Both bulbs require a (standard) 5Kv pulse to light. (Same as all MH and HPS bulbs) A MH ballast is what would be needed for a LEC/CMH.
HPS requires a special ignitor because of the arc tube length.
 
Yeah the linked is a conversion bulb and it runs a bit higher current and is less efficient than a straight up CMH

how ever i found that i can modify my hps ballast to essentially link out the ignitor making it a MH Ballast.

yipee no extra expense
 
Yeah the linked is a conversion bulb and it runs a bit higher current and is less efficient than a straight up CMH

how ever i found that i can modify my hps ballast to essentially link out the ignitor making it a MH Ballast.

yipee no extra expense

Both bulbs are 99.9% = in their efficiency 94v/3.35A vs 100v/3.15A ... both bulbs = 315W output.
The reason for the slightly smaller voltage on the first tube is due to the arc tube length...

:high-five: other than that they are the same.
 
I had this in my topic Bulb

Wondering if it can be used? Colour temp looks great.

So these things do cause fires huh, the op is dead? House burnt down? Or globes were ok? Im just interested to know... Thinking to try same... Also how do they go with the 320 & 330 w philips digi cmh? Im scared to try guys, in need of reassurance... Pls help
 
So after some 30 mins reading there are 2 types of CMH Lamps that can be used
  1. 315W (CRI 90+) specific for Growing - Requires its own Digi Ballast
  2. 400W(Conversion Bulbs in varying Wattage's with a CRI 80) - Can be run on a Standard MH Fixture (Magnetic Balasts Only I believe)
The Conversion Bulb would be the easiest option if you have an old MH Ballast (Not HPS - although I have several which are interchangeable Cannatronics "The Illuminator" 400w & 600W).

Think I will pick up One of These @ £37 and try it out....Certainly cheaper than trying a Philips Agro 315W @£90 with E40 CMH adapter

Anyone with more knowledge wld love to hear ure 2cents worth
 
So after some 30 mins reading there are 2 types of CMH Lamps that can be used
  1. 315W (CRI 90+) specific for Growing - Requires its own Digi Ballast
  2. 400W(Conversion Bulbs in varying Wattage's with a CRI 80) - Can be run on a Standard MH Fixture (Magnetic Balasts Only I believe)
The Conversion Bulb would be the easiest option if you have an old MH Ballast (Not HPS - although I have several which are interchangeable Cannatronics "The Illuminator" 400w & 600W).

Think I will pick up One of These @ £37 and try it out....Certainly cheaper than trying a Philips Agro 315W @£90 with E40 CMH adapter

Anyone with more knowledge wld love to hear ure 2cents worth
I run 10 ...315 watt cmh bulbs on 400 watt hps ballasts.........all day everyday....they only use 357 watts maximum....my digital.ballasts only use 345 watts each....i have 4 of those....
 
I run 10 ...315 watt cmh bulbs on 400 watt hps ballasts.........all day everyday....they only use 357 watts maximum....my digital.ballasts only use 345 watts each....i have 4 of those....
Hi. How long do you use 315w cmh bulb on 400w hps ballast? I wonder if I use double ended 630w cmh bulb on 600w hps ballast. That's works?
 
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