WorldwideHIDCollectorUSA
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HID, LPS, and preheat fluorescents forever!!!!!!
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| From what I have been aware of, there were T8 energy saving alternatives to the European 2 foot 20w T12 fluorescent tubes, European 4 foot 40w T12 fluorescent tubes, 5 foot 65w/80w T12 fluorescent tubes, and 6 foot 75w/85w T12 fluorescent tubes. After knowing all this information, I wonder why there were no energy saver T8 alternatives to the British 8 foot 125w T12 fluorescent tubes and why 100w energy saver T12 versions were made instead.
If a T8 alternative was made, it would probably have a power rating of roughly 112w or 113w since most of the T8 alternatives to European T12 tubes were made to use 10% less energy compared to the original T12 tubes.
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Desire to collect various light bulbs (especially HID), control gear, and fixtures from around the world.
DISCLAIMER: THE EXPERIMENTS THAT I CONDUCT INVOLVING UNUSUAL LAMP/BALLAST COMBINATIONS SHOULD NOT BE ATTEMPTED UNLESS YOU HAVE THE PROPER KNOWLEDGE. I AM NOT RESPONSIBLE FOR ANY INJURIES.
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RRK
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Roman
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| Probably because tube current density was already on a high side for T12, reducing tube to T8 will make things even worse. Also may be for a long T8 tube the ignition and burning voltages will be too high to work reliable with a choke from 240V mains.
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WorldwideHIDCollectorUSA
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HID, LPS, and preheat fluorescents forever!!!!!!
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| Even the full wattage 8 foot 125w T12 tubes in the UK also had an arc voltage drop that was too high to be used on a simple choke ballast alone. As a result, they needed series capacitors to be able to operate on a 220v-240v series. hoke ballast.
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Desire to collect various light bulbs (especially HID), control gear, and fixtures from around the world.
DISCLAIMER: THE EXPERIMENTS THAT I CONDUCT INVOLVING UNUSUAL LAMP/BALLAST COMBINATIONS SHOULD NOT BE ATTEMPTED UNLESS YOU HAVE THE PROPER KNOWLEDGE. I AM NOT RESPONSIBLE FOR ANY INJURIES.
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joseph_125
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| That was my hunch too, the thin 8ft tube was probably too much for reliable ignition on a 240v choke. A T8 8ft lamp was developed for 120v systems as the typical gear used allowed for a 500-600v starting voltage. On one of the spec sheets I found for the 8ft HO lamp, probably the most similar to a theoretical 8ft T8 replacement for 125w lamps, the listed minimum OCV for starting was 550v. The listed arc drop was 216v.
I'd imagine current density wasn't too much of a problem as 8ft T12s here had a VHO version running at 215w. As for the 8ft T8s, there was a HO version that ran at 86w.
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« Last Edit: April 19, 2023, 12:46:25 AM by joseph_125 »
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dor123
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Other loves are computers, office equipment, A/Cs
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| Also: A 8ft T8 would be very fragile because it is very long and thin.
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the international date format (dd.mm.yyyy).
I lives in Israel, which is a 220-240V, 50hz country.
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RRK
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Roman
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| Also, 8ft tubes even in its original T12 diameter seems to be used with a step-up transformer on an rapid/instant-start circuit. I am not sure if a non-standard 160V glow starter was available. Moving to T8/krypton fill would probably make this tube to fail to start on its intended circuit. Here is a circuit from an old Mazda UK catalogue. Also, AFAIK, there is no T8 descendant for 80W tube (0.865A) in Europe, too. At least in wide use. 20W has become 18W T8, 40W -> 36W T8, 65W -> 58W T8
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« Last Edit: April 19, 2023, 01:15:06 AM by RRK »
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WorldwideHIDCollectorUSA
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HID, LPS, and preheat fluorescents forever!!!!!!
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| From what I know, there certainly were dedicated starters for the 8 foot 125w T12 tubes such as the Philips S16 starter.
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Desire to collect various light bulbs (especially HID), control gear, and fixtures from around the world.
DISCLAIMER: THE EXPERIMENTS THAT I CONDUCT INVOLVING UNUSUAL LAMP/BALLAST COMBINATIONS SHOULD NOT BE ATTEMPTED UNLESS YOU HAVE THE PROPER KNOWLEDGE. I AM NOT RESPONSIBLE FOR ANY INJURIES.
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RRK
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| Yes, datasheet says threshold is 170V. Seems to be a very British-specific thing. Also, may be an idea to use S16 to run T5/28W HE on a magnetic ballast, as it was discussed uera some time ago.
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James
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To properly answer this question I would refer you to the excellent paper 'The Alchemy of Fluorescent Tubes' by J.W. Bessant of 1975. See Thorn Lighting Journal No.14 pages 5-8. Written by a Product Marketing Manager at a time when commercial people really understood the fundamental scientific technologies of the products that funded their salaries! |
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« Last Edit: April 19, 2023, 04:31:04 AM by James »
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RRK
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| Thanks James!
Have these 100W T8 tubes survived commercially?
In USSR and ex-USSR there never was a T12 tube with more than 80W. 80W were not particularly efficient, and just moderately popular in street and factory lighting, compared to the ubiquitous 40W ones used practically everywhere. Also, a reduced current 65W T12 tube was mentioned in various catalogs, but honestly I never seen one in real use. The only one bent tube in real use was 30W T8 one. When USSR was disbanded, 80W T12 tubes gradually have fallen out of favor, and imported, and then local 58W T8 tubes gained much popularity.
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James
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| The 8ft 100W T12 Krypton:Argon lamps were indeed marketed with great success in Britain, and superseded many of the older 8ft 125W installations. It was only a couple of years ago that they began to be phased put.
It is interesting that USSR also had the 5ft 80W T12. That was another characteristically British tube. Of course when the Europeans introduced the 5ft 65W T12 (which was their first popular 5ft tube) it was also adopted in Britain, but most of Europe never had the 80W predecessor. It seems unusual that USSR should have adopted it.
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funkybulb
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| What get me that our 95 watt 8 ft supersaver or econowatt High output tubes is just very close to your 100 watt T12 tubes
That the UK has. I tried it in my pop pack with out the series cap and it strike up just fine.
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No LED gadgets, spins too slowly. Gotta love preheat and MV. let the lights keep my meter spinning.
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marcopete87
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From what I have been aware of, there were T8 energy saving alternatives to the European 2 foot 20w T12 fluorescent tubes, European 4 foot 40w T12 fluorescent tubes, 5 foot 65w/80w T12 fluorescent tubes, and 6 foot 75w/85w T12 fluorescent tubes. After knowing all this information, I wonder why there were no energy saver T8 alternatives to the British 8 foot 125w T12 fluorescent tubes and why 100w energy saver T12 versions were made instead.
If a T8 alternative was made, it would probably have a power rating of roughly 112w or 113w since most of the T8 alternatives to European T12 tubes were made to use 10% less energy compared to the original T12 tubes.
James wrote about this in Krypton section: http://lamptech.co.uk/Documents/FL%20Gases.htm |
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