Lighting-Gallery.net
General => General Discussion => Topic started by: HomeBrewLamps on December 22, 2017, 07:59:22 PM
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I dont have proper gear... would a 70W hps ballast work? I will post pics of them soon... gonna eat dinner... but I figured i'd ask the question while its still at a decent hour of the night...
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Maybe with a 50W metal halide ballast (magnetic only) and be sure to deactivate the ignitor by disconnecting the neutral and capping it off. Usually small wattage MV/MH equivalents are that a MV lamp will run on the next downward available MH ballast, but without the ignitor.
PS if you don't deactivate the ignitor, it will blow your starting resistor upon hot restrike, among other bad things in your MV lamp.
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At the moment I don't really have anything below 175W ballast wise for MV/MH... lowest wattage ballasts I have are for 70W HPS...
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I tried it on 70W HPS gear and it lit and warmed up... but then it started cycling... So i guess i'll wait to find some 50W MH gear or 75W MV gear... like ya said sol...
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Ditto well the lamp need 130 volt 630 mA
And hps lamps is 55 arc volt meaning ballast
Is supply half the voltage to the lamp.
Ok 75 watt ballast is very hard to find
And 80 watt MV ballast for it will be wrong
For it too as it use 800 mA
Best thing to do is get a 70 watt european fluorescent choke and 240 volts. It will be close to it spec
Unless u find a 50 watt MH magnetic gear like Sol said.
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Low wattage mercs don't work on low wattage HPS ballasts. :( Is it a clear lamp?
Also, you could use an F40T12 RS ballast but it would be underdriven.
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Low wattage mercs don't work on low wattage HPS ballasts. :( Is it a clear lamp?
Also, you could use an F40T12 RS ballast but it would be underdriven.
posted a pic of it earlier... not really clear but you can see a bit through it.. http://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=0&pos=5&pid=140549 F40T12 ey?? how underdriven would that be?
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I have seen some 75W mercury postline ballasts on Ebay recently, but they are over $100 and are 277V only.
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I have seen some 75W mercury postline ballasts on Ebay recently, but they are over $100 and are 277V only.
Argggg both hundred buck and a voltage thats a pain in the arse to use.... ughhhh
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With European gear, i think something like either 58W T8 ballast (110V 670mA, would be less than 670mA with higher voltage lamp) or 2 26W PL-C ballasts in parallel (~100V, dont remember exactly, 320mA) would work..
Do you have any of that over there ?
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With European gear, i think something like either 58W T8 ballast (110V 670mA, would be less than 670mA with higher voltage lamp) or 2 26W PL-C ballasts in parallel (~100V, dont remember exactly, 320mA) would work..
Do you have any of that over there ?
I dont have any of that on me... but it might exist in the Americas Idk... I don't really specialize in the fluro department lol
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Is there any 5ft T8 or T12 non-HO lamp in the US ?
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Believe so... I know for sure we have non-HO T12, never personally encountered a 5ft T8 lamp though... Does not mean we don't have them though...
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Believe so... I know for sure we have non-HO T12, never personally encountered a 5ft T8 lamp though... Does not mean we don't have them though...
5ft T8 does exit here and is mostly used in refrigerators and freezers in stores.
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posted a pic of it earlier... not really clear but you can see a bit through it.. http://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=0&pos=5&pid=140549 F40T12 ey?? how underdriven would that be?
Well, considering how a 50w MV lamp I tried wasn't all that bright (probably around the same as a 75w incandescent) it would probably be pretty dim. If you have money you can spend, you can get a 50w PSMH ballast and disconnect the ignitor. They are currently available on 1000bulbs.com for $26, but shipping will probably be around $9. (That's what it is for me)
I have seen some 75W mercury postline ballasts on Ebay recently, but they are over $100 and are 277V only.
Well then, I guess I was lucky to get one in 120v. I just don't understand why they think they are going to get that much for a ballast that is next to useless to collectors, and is completely worthless to contractors.
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"next to useless to collectors"
Why ?
And it would be usefull for repairs of setups where same ballast was allready installed and failed
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"next to useless to collectors"
Why ?
And it would be usefull for repairs of setups where same ballast was allready installed and failed
I have 3 277V 100W HPS ballasts... I've not found much of a use for them... I actually wanna sell them off at some point they work on 240V but that is not practical for me since we mostly use 12OV, therefor they're quite literally Next to useless lol... Not even sure if they were driving the lamp at full power while on 240V.. I kinda doubt they were... Also I don't really service existing 277V installations....
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Mannnn.... I still really wanna properly light this lamp... WOuld I be able to put a resistor of some sort on a 175W ballast to reduce it to proper spec? or would that ruin the ballast? Or... is there some way to make an F40T12 ballast not under drive the lamp?? what If I used an F32T8 electronic ballast I recently obtained? would that overdrive or underdrive it? if it overdrives could I put a resistor to reduce the current a bit?
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I'll keep an eye out on a ballast for ya.
Yea seems like 277v is common with the 75 watters. Here's another 277v one, but it's much more reasonable:
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F181224221437 (https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F181224221437)
If you can figure out how to get one:
http://www.damarww.com/product.asp?sub=71&dep=75W%20M.V.%20Ballasts&prod=23515A (http://www.damarww.com/product.asp?sub=71&dep=75W%20M.V.%20Ballasts&prod=23515A)
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Mannnn.... I still really wanna properly light this lamp... WOuld I be able to put a resistor of some sort on a 175W ballast to reduce it to proper spec? or would that ruin the ballast? Or... is there some way to make an F40T12 ballast not under drive the lamp?? what If I used an F32T8 electronic ballast I recently obtained? would that overdrive or underdrive it? if it overdrives could I put a resistor to reduce the current a bit?
Forget the F32T8, it is too far away (too low current, the lamp has too low voltage for the F32T8 ballast, the MV lamp may not like the HF supply)
Two F40T12 ballasts of a bit lower ballast factor (0.7..0.8 or so) in parallel (those two outputs should really work in phase and the ballast should not be designed for series pairs) should work.
Using the 175W ballast is tricky:
In theory it may work, but in the real life you will face some design problems.
The only reasonable way is to use the "175W" ballast just as a step up transformer and add the ballasting impedance behind.
First conditin for success is, the ballast is capable to operate open load without any significant input current. If this condition is not met, you will likely face problems with ballast overheating. So then assume for now it is not dissipating anything significant. The HPF HX type will most likely need the PF capacitor disconnected (you won't need it in the 75W MV setup). When trying this, youwill have to measure the OCV, you need it later.
The added ballasting impedance could be a capacitor (in place of the original one if it is the case of CWA), but it would have to be of significantly lower value. Because of the leakage inductance of the transformer part, you would have to determine the value empirically, the good starting value would be half of the "175W" capacitor in case of CWA or 1/(3*2*pi*60*sqrt(OCV^2-110^2)/1.6) in case of a HX type.
Or you may use a resistor (a 240V incandescent,...) as the ballasting impedance, the resistance then should be about (OCV-115)/0.75. Look on the incandescent chart (http://lamptech.co.uk/Documents/IN%20Voltage.htm) to determine how the incandescent resistance will change with the voltage across the incandescent (about the OCV-110) compare to the incandescent rating.
Then try to assemble the setup and empirically adjust the impedance (capacitor value and/or incandescent total power rating) so you get the correct 0.75A through the MV arc (or something close to that).
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I'll keep an eye out on a ballast for ya.
Yea seems like 277v is common with the 75 watters. Here's another 277v one, but it's much more reasonable:
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F181224221437 (https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F181224221437)
If you can figure out how to get one:
http://www.damarww.com/product.asp?sub=71&dep=75W%20M.V.%20Ballasts&prod=23515A (http://www.damarww.com/product.asp?sub=71&dep=75W%20M.V.%20Ballasts&prod=23515A)
Thankyou...
That last link you sent looks interesting... Not sure how hard that'd be to obtain... would they allow residential user to buy that? or would I have to pretend I'm some sort of company? ... thankyou for the detailed explanation Medved, I do have a low power factor ballast And I do know where to obtain another one... I may try that soon...
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Thankyou...
That last link you sent looks interesting... Not sure how hard that'd be to obtain... would they allow residential user to buy that? or would I have to pretend I'm some sort of company? ... thankyou for the detailed explanation Medved, I do have a low power factor ballast And I do know where to obtain another one... I may try that soon...
Lightbulbdepot appears to have them, but no indication on price or if they are in stock. If I were you I would contact the Damar company first, they still make all sorts of uncommon lighting equipment and they might have a few NOS 75w merc ballasts in stock.
https://www.lightbulbdepot.com/products/details/i/23515A/?subId[]=71&dept[]=75W+M.V.+Ballasts&sortBy=default&pageNum=1&itemsPerPage=10&offset=0&returnPage=products%2F