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Lamps => Modern => Topic started by: form109 on December 31, 2008, 06:32:45 PM

Title: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on December 31, 2008, 06:32:45 PM
i recently purchased a Lithonia 70 Watt HPS area lighting fixture,at the same time i also purchased a regent H-38-100-MDX 100 Watt Delux White Mercury Vapor Lamp,i wanted to see how
the mercury vapor lamp would behave on a high pressure sodium ballast,so i screwed it in the socket,the lamp started up red and warmed up to a cool white color,as expected,howeven a minute after reaching full brightness,the arc extinguishes,i,ve observed this closely and the lamp cycles on the 70 Watt HPS ballast,why is this so?
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: don93s on December 31, 2008, 06:43:33 PM
When a MV warms up, it needs 130v across the lamp to stay lit which means the ballast needs an open voltage of over 200v. Your HPS ballast is only 120v open output since HPS lamp only needs 55v across it when fully warmed up. However, if you ever decide to check with voltmeter, be sure to disconnect the ignitor or meter will be damaged!

If I recall, lamp voltage must not exceed 2/3 of ballast open voltage or it will cycle.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on December 31, 2008, 07:05:01 PM
does running the Mercury Vapor Lamp in the fixture cause harm to the Ballast?

im already sure if i continue using the lamp,the cycling will kill the ignitor.

the label says the ballast provides 1.6 Amps,what is the opperating current
of a 100 watt mercury vapor lamp?
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: don93s on December 31, 2008, 07:57:25 PM
I doubt running MV will hurt the ballast, but yeah the cycling will wear the ignitor.

The operating current for a 100w MV is around .85-.95 amp fully lit, so yeah it is being overdriven when fired up on 70w HPS.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on December 31, 2008, 08:29:49 PM
Thanks,Don!!!
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: TudorWhiz on January 01, 2009, 04:22:41 AM
also depending on ignitor, if its a 3 contact ignitor it may damage the ballast from cycling...but 2 contact ignitor will NOT damage the ballast
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on January 01, 2009, 04:25:24 AM
well its a 3 contact starter,but i only let it cycle 3 times so it probably didnt hurt the ballast or ignitor at all.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: lightman64 on January 01, 2009, 07:15:20 PM
i wouldn't do that myself, for fear of expolsion or something bad.....
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on January 01, 2009, 07:21:28 PM
there's no risk of lamp explosion at all,the only bad thing that will happen is possible damage to the ballast,and certain destruction of the ignitor if i let the lamp continue opperating on the ballast,it was just a test to see how the lamp would look,until i get a  proper replacement bulb.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: lightman64 on January 01, 2009, 07:22:49 PM
oh ok. well im not as expercened in sodium vapor as you are. i mostly deal with mercury vapor.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on January 01, 2009, 07:33:10 PM
i wouldnt say im the most experienced,as this is my first High Pressure Sodium Fixture,the voltage provided by the hps is simply to low to keep the mercury vapor lamp lit.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: lite_lover on January 01, 2009, 07:45:58 PM
Yep,the voltage is too low to stay lit. Are you planning to get a 100W MV ballast or fixture?
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on January 01, 2009, 07:52:01 PM
Yep,the voltage is too low to stay lit. Are you planning to get a 100W MV ballast or fixture?

i would but 100 watt mercury vapor fixtures seem to be more expensive,only the 175 watt is avaliable around here,and i cant find a 100 watt mercury ballast,i might try metal halide.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: mercuryvaporisking on January 14, 2009, 11:59:33 AM
If you did not disconnect the ignitor before operating the MV bulb then you probably fried the Starting probe in the bulb. Try it out on a regular ballast to see if it will light anymore. What I do at work is if a ignitor ever goes bad on our 100watt pulse start MH lights I will install a 175watt probe start bulb on the existing 100watt pulse start ballast and it will work fine. Not full brightness but I have had 2 going now for almost a year and no problems. The color is off from the others but same amount of lumens,It's either this or convince them to get replacement ignitors which they don;t they just get new ballast instead, So why waste a $80 ballast cause of ignitor failure? I keep them going. I also tried a MV bulb on a HPS ballast and forgot to take the ignitor off and I cooked the starting probe in the MV bulb so it was useless afterwards without an ignitor.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on January 14, 2009, 02:19:26 PM
the starting probe wasnt fried,however during the off periods of cycling,the ignitor would make a weak arc appear outside the arctube.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: TudorWhiz on January 15, 2009, 06:37:54 AM
You can always easily replace the ignitor (starter) they are replaceable......keep the same ballast but replace the starter....
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on February 27, 2009, 09:25:33 PM
i am keeping the 70 Watt HPS ballast....the ignitor crapped out on me so i gotta find a new one! :)
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: lite_lover on February 27, 2009, 11:11:43 PM
The ignitor already crapped out? You have been doing too many experiments with this ballast. :P
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on February 27, 2009, 11:47:44 PM
its a Chineese Ignitor,so what do you expect? ;D....i only ran that 100 watt Merc in it one time..and i did stick a 60 Watt incandescent lamp in the socket to see what it would do....it was gonna go out eventually,the ignitor is just an extra part to go bad....i will get a much better ignitor...and replace that Crappy Polor Lights lamp. :)
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: lite_lover on February 28, 2009, 12:23:45 AM
Lol yeah those Chinese ignitors >:(. I had the same situation with a 70W HPS Castor ballast and ignitor,the ignitor lasted about 8 months,I replaced it with a good quality Advance ignitor.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: Medved on February 28, 2009, 03:27:06 AM
The MV will wear a lot, because cycling and there is an additional risk you start and arc outside the arc-tube due to high voltage from the ignitor during hot-restrike attempts...
In Europe, as the SON/MH70W is 1A/77V (the US one 1.5A/55V) work well the setup using SON70W ballast, it gives 0.9A to the MV100 (spec is 0.95 if i remember well). As EU SON70W have the same spec as pulse-start MH70W and these are the same worldwide (1A/77V), i think the "pulse-start MH70W" (i'm not familiar with ANSI numbering) HX ballast with disconnected ignitor will work (OCV around 230V, forcing 1A into 77V lamp, so it should force 0.9A into 130V lamp)...
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on February 28, 2009, 12:51:39 PM
i dont think the risk of an arc forming outside the arctube is all that great,the ignitor does not provide enough current to strike an arc in the outter bulb,not saying it isnt possible,as little weak,nearly invisable streamers do form between two pieces of the frame,but nothing damaging,like melting the frame.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: icefoglights on February 28, 2009, 01:14:54 PM
Ignitor crapped out huh?  Sounds like a Caster to me  :P
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on February 28, 2009, 01:20:01 PM
the 70 W Ballast is a Caster,the ignitor has no labels that identify Brand,but its probably a caster.....the ballast is actually really good,it runs nice and cool!
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: lite_lover on February 28, 2009, 02:45:05 PM
My Castor ignitor is a white square one,if yours is like that it would be a Caster as well.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: form109 on February 28, 2009, 02:55:12 PM
yep...its a square white plastic casing.
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: Solanaceae on June 07, 2015, 09:32:17 PM
My cooper fixture also had a crap igniter. It lasted three years since it was installed in 2012 and it died bout a week ago. I noticed it had trouble starting so once it died I gutted it and installed my 100w merc ballast. It looks a lot like an authentic NEMA 175w bucket lite, but scaled down a bit.  :P
Title: Re: Running Mercury Vapor Lamps on High Pressure Sodium Ballast
Post by: tolivac on December 02, 2015, 12:47:23 AM
I have a Lithonia (Chinese built-has Caster components)100W MH light whose igniter failed-runs 100W mercury lamps just fine-rescued from the junkbox!