http://info.eyelighting.com/blog/bid/345200/Are-Mercury-Lamps-Still-Legal

I found this wonderful article about the "Mercs" from Eye Lighting (Iwasaki).  I hope everyone enjoys reading it as much as I did.  I think whoever wrote it is spot on, and it is a great article.

I saw that article and saw that it was very informative and a pleasant read.  Long live !

Heres the reason why EYE Iwasaki still continues to pump out excellent quality mercury lamps, while all other manufacturers have went the cheapest possible route on theirs. Its the people who work at EYE, like the author of this article who still sees the benefits of mercury vapor, that and possibly a bit of nostalgia in there too 

Its great that we have such people in the industry

Its great that we have such people in the industry

+1 

I like that Iwasaki is still committed to the MV technology, and therefore their products are the first ones I'd consider buying. I still have yet to find an actual bill that mentions banning MV lamps in 2016, so if someone could direct me to one, I'd appreciate it. If one doesn't exist, well, maybe there's a future for MVs.

Maybe the governments ban on is a sham that's getting us collectors into overdrive about buying into all their crap (Chinese mercs, but we're better than that). Plus, the Chinese feit ones at lowes, for example, the 175w utilitech named feit lamps have the arctube of a 125w merc, therefore causing the ballast to heat and stress more. I have noticed that the fake westy 100w mercs of Chinese making have an arctube only 75% of a tried and true, high quality, us made westy from the 70s or 80s. They make people slowly burn their own ballasts out and that creates the "Mercury vapor is evil" image, causing the switch over to LEDs. Just my (somewhat crackpot) theory.
Another thing I noticed is people are going crazy over metal halides being more efficient (they are pretty efficient, albeit with a slightly higher lumen depreciation rate than a ). But, I'd rather have a lamp that glows dim at eol, rather than exploding and sending glass hurdling at supersonic speeds. The guarded arctubes and ones with plastic coats to prevent stray particles from escaping will work, but the higher the wattage, the higher risk for more damage to the outer envelope (this holds true for those "cram lamps used in shoebox lights).
The government says that the mercs are "outdated and inefficient". The government described itself there, so therefore it shall ban itself.

The thing with burning out ballasts seems plausible to me. Can you compare arc voltage / current / line current in the China Merc vs a proper Merc in about the same staste of wear ?

Here we get the China 125W mercs as they are (our mercs are supposed to be 125W by design), what i noticed is just incredibly fast Lm deprecation. The China Mercs go from full power down to significant light output drop in a year or two, and down to useless glow in just a few years. A proper Merc would of jsut started going down a little in output in this time.... What changed is, they dont use anymore the whitening emitter on the electrodes but the basic one, so the arc tube wtarts going black from the 1st day, instead of going white and only blackening when it comes near EOL as in a good Merc

If the 175W Merc is really an European 125W in disguise, it should work fine on 100W Mercury and i think also 100W Metal Halide ballasts. (Here it can also be used on 70W and 100W HPS ballast, but its not the same HPS as in the US)



In many places you dont really need the advantage of the Merc EOL mode (still lighting with lower output), and you can do with a lamp that abruptly starts to cycle or dies. For those applications the MH can well be a better choice....

There are protected MH lamps that won't explode at EOL, and if you use something like a cobrahead with glass refractor (and not plastic), it won't mind an exploding lamp anyway so you could as well use the unprotected MH

The other flaw I noticed in China mercs is that the electrodes are horribly undersized for their rating. The size of the electrode, in addition to the white sputtering emission coat, is pivotal for a long useful life. I was toying with buying the two pack of the China 175w 125w mercs and using them with an h38/44, or m90 ballast with disconnected Ignitor. The fake westies have been know to abruptly fail and the electrodes become embedded in the arctube. This effect is reminiscent of an electrode on a fluorescent tube running with is gear with zero emitter coating left. The electrodes get embedded in the glass, either causing the arctube to leak or the glass will seal back over over the remains of the electrode stem, isolating it and rendering the lamp useless. TL;DR: Chinese Mercury lamps suck.

"Another thing I noticed is people are going crazy over metal halides being more efficient (they are pretty efficient, albeit with a slightly higher lumen depreciation rate than a Mercury Vapor Lamp). But, I'd rather have a lamp that glows dim at eol, rather than exploding and sending glass hurdling at supersonic speeds. The guarded arctubes and ones with plastic coats to prevent stray particles from escaping will work, but the higher the wattage, the higher risk for more damage to the outer envelope (this holds true for those "cram lamps used in shoebox lights)."

I don't understand why so many people on here think that the typical EOL of metal halide is explosion. Its a far cry from common, in fact it so rare that in the thousands of MH fixtures of all types ive replamped over the years ive ony seen maybe a dozen situations of a ruptured arctube. And EVERYBODY lets their MH lamps burn until they completely fail/go out. I have never once met a business owner/company which group relamps their MH after calculating what time they'll be near max. average rated life. So for seeing tons of metal halide lamps burn WAY longer then they ever should, the arc tube rupture rate is almost nil. Just my 2 cents to give people an idea that this almost never happens. 

I've seen Walmart mh lamps where there are a few that were spot replaced and the rest were green and one was even glowing dim red. The thing I've heard is that cycles are also concerning. And does the arctube have a higher chance or explosion if the lamp is pulse or probe or does it make a difference? I have seen the arctubes that are two or more pieces and that poses more of a risk to me.

Arc tube explosions are known to happen, therefore you take precautions - use the lamp in enclosed lantern, or choose a lamp with internal shield. Then it is no longer a problem, whether it would happen rarely or every day



What determines the pressure in the arctube is in big part the lamp power, and that is related to the arc voltage - which tends to go up in aging lamps

At what voltage the lamp would go out. That depend on the ballast's ability to supply the increasing voltage - When the available voltage is less than what the arc wants, lamp goes cycling

I can imagine the available voltage to maintain the arc (at a current at which it will hold on) is loosely related to the ballast OCV (without counting in the ignitor voltage), but there is no hard set rule. I would guess a ballast with higher OCV would be able to get the arc to higher voltage, so higher pressure. I am not familiar with the US ballasts and their typical OCVs, but here it would be the same for Pulse start MH and Probe start Mercury (both of them being just a choke), and higher for CWA Probe start MH (being a step up transformer)

Ignitors can sometimes actually cause cycling. They are voltage controlled. The trigger voltage is chosen between the arc voltage of a good lamp and the ballast OCV, so when the lamp is struck (arc voltage) the ignitor stays off, and when the lamp is out (OCV) it works. As the arc voltage rises, it might reach the ignitor's trigger voltage - where the ignitor thinks that the lamp is out, and try to strike it. As it does, it places momentary load on the ballast parallel to the lamp (a semiparallel ignitor basically shorts the ballast output momentarily), this result in a dip in the ballast output voltage, and the lamp goes out

The 2 part arctube is not necessarily more prone to explode. It depends on the arctbe and on what it is filled with (to what pressure) in the particular lamp. Besides, if everything else is the same, it may take lower pressure to blow the 2 part arc tube, then it will explode with less force.....

And i have yet to see a 2 part Quartz arc tube. Ceramic arc tubes dont work at as high pressures, so the risk with them is lower

Our ocv of a metal halide ballast is around ~310 volts and a ballast is ~250 volts ocv, the ocv may fluctuate slightly based off if the ballast is quad tapped or not, and based on what tap you use on the former ballast type. Other variables may include: cwa ballasts and probe start ballasts. The cwa ballasts for ocv is 250v and an hx is 255v, so not too much of a difference there.
The ocv on my 250w cwa ballast, however, said that it varies from 205 to 285 volts, and it's a quad tapped ballast.
Also, due to the ~55 volts difference, a 125w can run on a 100w metal halide ballast, but with the Ignitor disconnected. The slight change of voltage can deliver ~10-30 more watts to a merc of the same wattage, depending of course on lamp current and voltage. Examples: * means disconnected Ignitor.
39w mh* ballast running a 50w
70w mh* ballast running a 100w
100w mh* ballast running a 125w
I'm not sure, but a 50w mh ballast may run a 75 or 80w lamp.

I found a 100W MH fixture in my junkbox-put it back into service running a 100W mercury lamp-Works fine.The MH ballast has a blown igniter.

I found a 100W MH fixture in my junkbox-put it back into service running a 100W mercury lamp-Works fine.The MH ballast has a blown igniter.

Does the ballast run any hotter than with a 125w or with a proper mh lamp? I would suppose you could start the mh by momentarily shorting the ballast output manually or by using a high wattage tanning bed starter.