Medved
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The Lm deprecation rate of old Mercs was way slower than today's cheap mercs (that are rated for 4 years), so 10 years is quite reasonable
When defining the end of life as when the lumen output drops to 70% (that is, how the system should be designed, otherwise the use of a lower power lamp is more appropriate), the old lasted barely 3 years or so (10hours/day cycle). For the same criteria the new lamps last 4 years. The main change was to use "whitening" agents in the emission reservoir mix, which make the tube blackening slower, but only till the reservoir depletes. Then the blackening usually "catch up" and even "overpass" the older designs, where such additive may have been longer lasting, but less efficient (so it looses the light output faaster). So yes, when you operate the laps 10+ years, it may happen the older design (with less efficient, but longer lasting "whitener" mixture) emits more light. But that is not what the lamps are designed for. The design goal is to prolong the life till the 70% light threshold, as that is the limit (to maintain a reasonable average efficacy)
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No more selfballasted c***
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Ash
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The older lamps i am talking about are the ones with the whitening agent. They dont use it anymore on the new ones - Today's Osram HQL 125W appear to be blackening from the 1st day in service, and in 4 years i'd say it is closer to 0% output than to 70% output
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Medved
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Osram HQLxxx is just a 3 year rated lamp. It contains the older agent, bt boosted power loading (optimized for maximum average efficacy for a 3 year service life, as was the standard since many decades ago; include the older lamps, there just the efficacy was lower even initially). The 4 year were the "HQLxxx-SUPER4Y" and it came here just as a last innovatiion before the greenbrainers shut the MV's down from the market.
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No more selfballasted c***
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Silverliner
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Here in the states, we got Westinghouse Lifeguard mercs with 20 years of use on them and only grey arc tubes. 2/3 of original lumens. European mercs are likely not as good due to smaller electrodes.
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Administrator of Lighting-Gallery.net. Need help? PM me.
Member of L-G since 2005.
Collector of vintage bulbs, street lights and fluorescent fixtures.
Electrician.
Also a fan of cars, travelling, working out, food, hanging out.
Power company: Southern California Edison.
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Ash
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I have a NOS Philips HPL-N 125W from 1998 or so. It is as bright, if not brighter, than any other present day 125W Merc. The color is really good. Identical 90s HPL-N's kept good output for over 10 years. Arctubes on broken lampsat ~10 years were different shades of grey
Present day 125W Mercs (mostly Chinese Osrams) go black from the 1st day - If a lamp is smashed after a year or two in service the arctube is black. Maybe they dont use the whiteing composition at all
The old - late 80s, 90s, maybe early 00s Mercs were superior to anything present today in every single parameter. Maybe except that Philips' HPL4 legend. And yep they did well their 10 years, whether rated or not. Todays Mercs may be rated for 3 or 4 years cause that is as much as a Cheepee Merc would go till the point of no usefull light at all, not even 70% maintenance. In 10 years i think it won't even start anymore
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AngryHorse
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Rich
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Yeah, ALL European HID lamps, from the 80/90s, were the best they could be, funny how they get them to that stage, (being the best on the market), then sell it all off to China, (along with their reputations)!!!
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Current: UK 230V, 50Hz Power provider: e.on energy Street lighting in our town: Philips UniStreet LED (gen 1) Longest serving LED in service at home, (hour count): Energetic mini clear globe: 54,050 hrs @ 10/2/24
"Beauty fades, dumb is forever".......Judge Judy
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Silverliner
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10 years is not bad, but got anything going after 20 years with just a 1/3 lumen loss?
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Administrator of Lighting-Gallery.net. Need help? PM me.
Member of L-G since 2005.
Collector of vintage bulbs, street lights and fluorescent fixtures.
Electrician.
Also a fan of cars, travelling, working out, food, hanging out.
Power company: Southern California Edison.
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Ash
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At what wattage ? I am about 125W here, but the relatively small lamps also have small arctube, all of which is quite close to the electrodes. Maybe the arctubes of higher power lamps stay cleaner in the center for longer, but im not aware of any such installations around that use old lamps in good condition to evaluate
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streetlight98
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Mike McCann
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My local utility National Grid has made no effort to start offering LEDs. They only offer HPS lights in 50, 70, 100, 250, and 400W. All remaining MV gets replaced upon servicing. If cities/towns want to go LED, they have to buy ownership of the existing NGrid lights (as NGrid leases them to the city; the electric company owns the existing lights). That way the city can install what they want and NGrid doesn't have to worry about fixing the lights anymore.
As far as my local utility is concerned, there's little money in street lighting anymore. It's more of a nuisance. They'd rather focus on their primary businesses: electricity and natural gas distribution. NGrid is letting their lights go at a loss too: about $1 per light (the cost was set by taking the original cost of the lights less "depreciation". Basically once the light is installed on the pole, it's not work anything to NGrid). The city actually ends up getting that $1/light back and then some when they scrap all the old lights. So NGrid is essentially giving away the lights. That's how badly they want out of the street lighting business.
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Please check out my newly-updated website! McCann Lighting Company is where my street light collection is displayed in detail.
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