Obsolete fluorescent light fittings

[broadgage]

Originally Posted by Tractorfan

I've sometimes wondered about fluorescents designed for 110volts such as those in the USA etc. Would the longer tubes be more reluctant to strike, or is the gear designed differently (greater inductance perhaps)? I've never tried my dual voltage ones on 110volts.

The smaller sizes of fluorescent tube will work from 110/120 volt supplies with a simple series choke and suitable glow or thermal starter.
This is actually more efficient than 220/240 volt operation as the losses in the ballast are less.

6 inch 4 watt
9 inch 6 watt
12 inch 8 watt
18 inch 15 watt
24 inch 18 watt
24 inch 20 watt
24 inch 40 watt
22 watt circular

Will all work on suitable switch start chokes from 110/120 volt supplies.
Longer lamps need either a higher voltage supply, or a ballast that incorporates a step up transformer.

[broadgage]

To add to the points above, fluorescent lamps used in the USA, either vintage or modern, are not allways on 120 volt circuits.

Homes and small busineses in the USA normally have a 3 wire AC supply that gives 120 volts for lighting and small appliances, and also 240 volts for larger loads.
Lighting in homes and similar premises is limited by law to 120 volts.

Larger business premises normally have a three phase, four wire supply at 277/480 volts. Fixed lighting in factories and offices is normally 277 volts.
277 volt ballasts are readily available in the USA for all the larger fluorescent lamps.

Most types of American 277 volt ballast will work fine on a UK 240 volt supply, the lower impedance at 50 cycles as compared to the impedance at 60 cycles, roughly compensates for the lower voltage.

[Zelandeth]

Hopefully I'll have something to add to this page shortly. Looks like I might have managed to save some late 60s (installed in 68-69) 3x20W and 3x40W recessed Quick-Start fixtures from a trip to the skip from a building nearby which is being demolished. Crossing my fingers that I can get hold of the diffusers as well, which are very thick and truly excessively heavy opal acrylic. I know from prior discussions with the engineers which used to maintain the place that the vast majority of them are still running their original ballasts. No idea who made them at this point, but I'll be interested to find out.

No idea at this point how many I'll end up with, but will be glad of anything! Hoping that a few Coughtrie SBF16 2x8W fixtures can be salvaged as well - many of those are recessed into solid ceilings though rather than just suspended on standard grid ceilings, so odds on them coming out in one piece are lower! Fingers crossed I can bag a couple of them as they're very good old units.

They did cause some consternation a couple of years back however when a younger engineer tried to replace some burned out tubes with T8s however...suffice to say that didn't work! The other trick was the sheer weight of the diffusers breaking the little tabs which held them into the ceiling grid, leading to the occasional diffuser deciding to fall out - usually set off by a strong gust of wind if a window was open. One on the desk opposite mine did that once - thankfully it was vacant - still totalled a keyboard (snapped clean in half) and scared the living daylights out of me though!

[Zelandeth]

The term "biting off more than I can chew" does spring to mind sometimes...Surveying my kitchen the day after picking this lot up was one of those times!

Somewhat to my surprise, the demo crew were actually very willing to help out, and I ended up with an awfully large amount of stuff. Now I've just got to figure out what on earth to do with it!

It took me two full car loads to get everything back - even in the Saab! Not often I find myself wishing for more cargo space there.

All of the fixtures in the offices were made by Atlas, and all are 40W T12 Quickstart. Including the 2' ones which are also take 40W tubes - even though most of them came with 20W tubes in...no wonder they've always had a tendency to fry tubes in a hurry! 40W 2' tubes aren't exactly common though, so I'll be needing to stock up before they disappear entirely.

The chaotic scenes below show what my tiny flat looked like when I'd got them home. Nearly killed myself that afternoon - the four foot fittings weigh 28kg apiece, and the two footers aren't much lighter. I live on the second floor too, just to add to the fun. That wasn't everything either - there was stuff left in the car too!

In the end, I picked up the following:

10 Atlas 3x40W 40W 4' Quickstart Recessed fixtures (two bodged with modern ballasts).
4 Atlas 3x40W 2' Quickstart Recessed fixtures (Two and a half of these had also fallen foul of Billy The Bodger - probably when someone tried to run an F18T8 in them...)
6 Coughtrie SFB16 bulkhead 2x8W Fixtures.
2 Coughtrie A120 Bulkhead fixtures. Reckon these would originally have been incandescent, but they've been converted to 16W 2D. Granted, the conversion looks a good quality job (switchstart thankfully), and the date code on it is 1984, so it's not done bad...

In addition to the fixtures, a black bin bag was supplied which was full of old linear incandescent lamps (odd as these weren't used anywhere in the building that I was aware of), and eight new (in the case of six not even opened) Osram/GEC made Cryselco 30W 3' fluorescent tubes. Again odd, as 3' fixtures weren't used anywhere in the building. Given that they're all brand new we reckon that they were bought in error. In 1980 or thereabouts given that the tubes are dated 1979.

So on with the pictures, as that's what you're all interested in.

[Zelandeth]

Going into a bit more detail, the vast majority of these are actually in very, very good condition. Save for the handful which have been vandalised by Billy The Bodger (58W T8 electronic ballast in a 2' fixture anyone? ...Running 20W 2' lamps...) anyway. Even those ones are physically fine, just need the right control gear re-fitted.

What *everything* needed (and in some case still needs) is a really, really good clean.

Attached you can see one of the 2' 40W units (well, the gear tray from one of them - they're almost self contained lanterns in their own right given that the lamps are held to the gear tray by terry clips), after I'd given it a good clean. Looks like new doesn't it - you wouldn't think it had seen 44 years of service...

Was interested to see in the SFB16 bulkheads that there are at least three distinct different types of gear fitted to these - imagine these were all ordered at the same time, still in an order of several hundred not surprising to see some variations.

Happy to snap more photos if anyone wants to see anything in particular. Need to get some more 40W 2' tubes though, only have two at the moment...

[Herald1360]

I wonder whether they were so keen to hand them over because they'd be "hazardous waste" which ain't cheap to dispose of.....

Or maybe even demo men feel a bit odd about consigning large amounts of perfectly serviceable gear to the tip.

[MrElectronicman]

Many years ago now I acquired some old fluorescent light fitting for my basement. They worked well for a year or so and then started to drip tar onto the floor. That's when I found out more about PCB's. Not really dangerous, unless the tar caches on fire, but these days I would not even have such things in my house.

[winston_1]

Originally Posted by kalee20

I can't see that somehow - fluorescent lamps need AC to work. If you use on DC, then the tube would probably be unevenly illuminated; also, the cathode would need to be permanently fed with some sort of heating supply (while the anode electrode would be hot due to electron bombardment with no gain). On AC the heat generated in an end electrode in 'anode' mode is made use of during the next half cycle when it's in 'cathode' mode.

I visited Calcutta back in 1971 and remember putting my neon screwdriver in a mains socket as I could judge 220v or 110v by the brightness and saw only one electrode had lit. Yikes I thought 220v DC mains. Had a wander round the hotel looking at the fluorescent fittings and saw that a large wire wound resistor was fitted in series with each. The original chokes were also present. There seemed to be no uneven lighting.
On DC I believe it is good practice to reverse the supply at every switch on.

[matthewhouse]

I just recently removed a 5' fitting, it is quite dirty and needs repainting. I was going to bin it, but the Ekco logo on the top persuaded me to clean it up. It still works, it just needs a new tube. The triphosphor lamp in the new fitting was three times brighter than the old one!

[broadgage]

Originally Posted by kalee20

I can't see that somehow - fluorescent lamps need AC to work. If you use on DC, then the tube would probably be unevenly illuminated; also, the cathode would need to be permanently fed with some sort of heating supply (while the anode electrode would be hot due to electron bombardment with no gain). On AC the heat generated in an end electrode in 'anode' mode is made use of during the next half cycle when it's in 'cathode' mode.

This is not the case in practice.
It used to be fairly common to use fluorescent lamps on DC, the light was even initialy, but tended to become uneven in time.
This was easily prevented by using a four position rotary switch to control the DC mains supply to the lamp. These switches had two on positions and two off positions, and a ratchet mechanism that only allowed the knob to be turned clockwise. The two on positions were wired such that the supply polarity was different in each position.
The user simply turned the control clockwise for on or off, thereby automaticly reversing the polarity each time the lamp was lit.

No heater supply is needed once the lamp is lit, the heater remains hot enough, presumably due to being bombarded with positive ions.

Back in the good old days, I used 18 inch 15 watt lamps from a 72 volt battery, with a series dropper resistance and a thermal starter.
A 24 inch 20 watt lamp could be used under favourable conditions, but not reliably with only a 72 volt supply.

[emeritus]

re #206, last year I took some duff fluorescent tubes to my local "civic amenity centre" and, beliving them to be hazardous due to the mercury content, asked where they should be put. I was told to simply put them in the rubbish container for non-recyclable stuff.

[broadgage]

Used tubes do indeed contain mercury and therefore should be recycled, however the amount per tube is very small and some authortities contend that recycling of small numbers is not worth while.
If the mercury is to be captured and reused, rather than released into the enviroment, then it is most important that the used lamps are sent INTACT to the recycling center.
If the lamps are broken in transit, as is often the case, then the mercury is released and the whole idea is rather pointless.

[line sync]

I thought id post some pictures of my mazda netaline striplight.
This light was still in use as a kitchin light until very recently.
Some good friends were renovating an old house and presented me with this light.
I,ve spent the past few weeks restoring the old light which includes
dismantling ,cleaning and rewiring .
This light uses a long lenght of resistance wire instead of the familiar ballast choke and you,d be surprised how hot it gets during use.
This light is similar in appearence to the one owned by lee (hunts smoothing bomb) except he,s uses a ballast bulb/starter arrangement and is older than mine.
See lee,s atlas light on page 143 of this thread.
Can anyone tell me why the skiny type 4 foot tubes wont work in these fittings ?
Its surprising to think that this light is approx 50 years old and if i get enough older type tubes in stock it could last another 50 years.

Robin

[keithinuk]

My father in law still has a bayonet fit fluorescent light, like the standard light bulb fitting, in his garage and still has some spear bulbs for it as will.
I don't know if this type is still used today.

[Tractorfan]

Hi,
Most modern tubes are designed to work with inductive or HF ballasts. A fitting that uses a resistance wire can't provide the initial high voltage pulse they need to establish the discharge. I think it's something to do with the design of the electrodes, the gas pressure (possibly higher) or the gas mixture.

Bayonet capped tubes haven't been available for many years, but adaptor caps are (or were) available to allow bi-pin tubes to be used in older fittings.
Cheers, Pete

[broadgage]

Bayonet cap tubes are no longer made as far as I know, but some suppliers may still have stocks.
The last large user of these lamps was London Underground, they no longer use them on any significant scale, but there are probably a few in forgotten corners.

The only tube to be regularly manufactured with bayonet caps was the 5 foot 80 watt version.

Flourescent lighting came into rapid use in the war to facilitate 24 hour production, and to allow basements and tunnels to lit well enough for fine work.
Bayonet caps were selected as these and the matching holders were already mass produced, under war conditions making larger volumes of an existing part is preferable to designing new components.
The 80 watt rating was selected for the same reason, to avoid special production of ballasts as these were identical to 80 watt mercury ballasts.

[Tim]

We are changing out all our 8 ft tubes and fittings at work.

Why?

Because they(and the tubes) are too long to fit in our electricians vans!

[emeritus]

Re #206 and #211, my civic amenity site does now have a specific container for CFLs and fluorescent tubes.

[matthewhouse]

Originally Posted by Tim

We are changing out all our 8 ft tubes and fittings at work.

The tubes are also very expensive now, £16-18 per tube is quite common, though at least they seem to last for many years.

[broadgage]

AFAIK 8 foot tubes are no longer manufactured or imported, due to energy saving rules.
Existing stocks may be sold or used without concern.
There is no regulation that directly prohibits 8 foot lamps, but there are minimum efficiency standards with which no currently available 8 foot lamps comply.