Fluorescent tube lamps

[flyingtech55]

Hi all


An elderly acquaintance of my gf asked me to help her with a problem she is having with the lighting in her garage.


She has two ceiling mounted 5ft fluorescent light fittings. One of them stopped working and an 'electrician' diagnosed a failed lamp. A replacement was fitted which didn't work so the fitting was taken down and a pendant light fitted instead. She is not happy with this solution and I was asked to have a look. Fortunately the fitting has been left propped against the wall but the original tube has been taken away and presumably destroyed.


I've checked the fitting and discovered that the starter is defective and normal operation is restored by fitting a new starter and a tube which I borrowed from my own garage.


The question is.....the original tube was the old 'fat' type tube. All the modern tubes, although they have the same pin spacing are the new 'skinny' type. If the tube rating is the same, is it in order to use one of the current skinny tubes in a fitting designed for the old 'fatter' tubes. I want want to avoid going down the LED strip light route. I would rather restore what she has/had if at all possible.


Thanks in anticipation.


TimR

[emeritus]

I would think you will be OK. It's usually the ones with the older starterless fittings that will only work with the fatter tubes. As it is for use in a garage, wiping the tube with wax furniture polish can prevent problems with reluctance to start in cold or damp conditions. I have avoided several unnecessary tube replacements by this simple procedure.

[JimmyMcgill]

Yes, a thinner one will substitute. I’ve done it a few times. The only problem I’ve run into is a plastic diffuser which was held on by actually clipping to the glass of the old thicker tube. As it’s in the garage (rather than say a kitchen) you could manage without a diffuser.

[paulsherwin]

I've also done this without problems.

[broadgage]

Agree that a slimline tube can almost always be used in place of a fat tube in fittings with a starter switch.
The correct slim tube will typically have a wattage about 10% less than the original fatter lamp.

A five foot fat tube will usually be rated at 65 watts, and the slim replacement at 58 watts.

Older five foot lamps were dual rated for operation on an older 80 watt choke or on the newer 65 watt chokes.
An 80 watt choke will over run a modern 58 watt lamp, but there cant be many 80 watts chokes still in use.

[The Philpott]

Agree with all the above. T8 tubes are worse than 'fat' T12's for being flickery at low temperature starts, but over about 10 centigrade they are more efficient.
If the ballast is rated '65w' it will cope with 58w.

Silicon spray can substitute for wax polish to ease cold starts, as can fitting a solid state starter such as a tubesaver.

(The LED 'upgrades' for tubes i have seen in B&Q have a much lower lumen output- which is why i haven't bothered.)

Dave

[flyingtech55]

Thank you for all the feedback so far. I've checked the choke and it is indeed an 80W choke. 80W tubes are still available but only with some difficulty. The unit is installed in a garage and is used only occasionally and for fairly short periods. I'm really quite annoyed that the original tube was scrapped when the original fault was almost certainly a failed starter. How long do you think the tube will last being over run in this application?


TimR

[broadgage]

I am not aware of any reliable data as to how long a modern 58 watt lamp will last on an 80 watt choke, but I would expect several thousand hours.
If the choke has tappings for different mains voltages, then select the highest voltage, probably 250 volts, even if your mains voltage is less than this.

[flyingtech55]

There don't appear to be any tappings on the choke. It's just the two connections. It can also work with a 125W 8ft tube as well according to the label on the choke. The fitting is very well made out of quite thick steel. It is certainly quite heavy. I can't find a date on it but I wouldn't be surprised if it doesn't date from the sixties.

[Julesomega]

Originally Posted by The Philpott

The LED 'upgrades' for tubes i have seen in B&Q have a much lower lumen output- which is why i haven't bothered
Dave

That got me thinking, I've just asked for a quote to replace some double batten fittings in a room in a communal building where we want it at least as bright as the old fat tubes, by fitting LED types. I've been perusing the Toolstation and Screwfix catalogues and I see that for a given tube length you can get different power ratings with proportionate light output. Fluorescent fittings now all have HF ballasts and a typical 5' 58W tube is spec'd at 5200lm. Change to a twin fitting, using 24W LED tubes will give the same light o-p as a single fluorescent

If however you change to a batten with a fixed LED array you can get some really good light, for ex the Sylvania Single 5ft LED Batten gives an impressive 6500lm so I'd better get back to the electrician and ask for these or equivalent. You'd need two of these to replace a twin fluorescent

[Glowing Bits!]

I can understand not wanting to mod the original fixture but if the choke is rated at 80w, it must be very old by now.
The T8 tubes are starting to be sold off cheap at Screwfix primarily because they are about to become obsolete, get them while you can.
T12 tubes are c**p compared to T8's, they are considerably dimmer while consuming more power than their smaller counterparts.
If the OP requires some electronic starters, let me know, I have a small stash now rendered obsolete, the whole garage has gone LED.
My recommendation is to use Crompton LED tubes, they have a long guarantee and are the brightest I have managed to find, the output is slightly lower than florry tubes but they use half the power, plus no waiting for it to come on!
Below are some pics of the said tubes in operation, the first pic is of a 5 foot tube, it is dimmer than usual due to smoke in the room settling on the tube itself, it is brighter in real life than the pic suggests.
The second pic is of the walkway/dumping ground area, it is a 4 foot tube in clean condition, to show how bright these things are, this pic is more accurate than the first one.
Hopefully, it will all work out at the OP's end.

All the best whichever way things go, Rick.

[Lancs Lad]

Ooh, Rick, please may I just ask - what's that vacuum cleaner in the foreground, on the left in front of the plantpot?

Is it a Hoover Senior, perchance? Like the one in this pic?

Sorry to briefly hijack the thread

[Glowing Bits!]

It's a 1937 Hoover Junior.
It's best not to discuss any more about contents of rooms or the mods may close this thread.
I don't mean to be a kill-joy but the mods frown upon things going off-topic.

[The Philpott]

An 80w choke/ballast with a 58w tube..? That scenarios worries me- there was an issue with (4 foot) 40w tubes being replaced with (32w? * 34w?) tubes some years ago- i think it was in the US- which resulted in either the choke or the wiring getting too hot. A 36w tube can be used with a 40w choke, but these tubes* pushed it too far.

Perhaps a photo of the choke..?

I may have a spare 65/58w choke loose.

Dave

[Glowing Bits!]

I think Dave's idea is a good one, change the choke if need be!
I can't honestly see how the tube can last long with a rather large mis-match.

[raditechman]

I just had a quick search on Google and 58w choke ballasts for switch starting are about £6-8 so you could replace the choke at not too much cost.
There must be many being scrapped as lighting is replaced with LED's, but it is a case of finding one when you want it.

I would not use a 58w tube with an 80w choke ballast.

John

[bionicmerlin]

If you get stuck I’m sure I got a 58w choke .subject to checking ,yours for the cost of postage.
Andy

[flyingtech55]

Thanks for all your input(s) so far. A lot of thoughts and possibilities to consider. I have found a supplier of the older, fatter type 80W tubes which can be purchased singly but how the supplier dispatches them is a question I shall ask them tomorrow.


Thanks to all so far.


TimR

[GroovyG]

Originally Posted by Julesomega

That got me thinking, I've just asked for a quote to replace some double batten fittings in a room in a communal building where we want it at least as bright as the old fat tubes, by fitting LED types. I've been perusing the Toolstation and Screwfix catalogues and I see that for a given tube length you can get different power ratings with proportionate light output. Fluorescent fittings now all have HF ballasts and a typical 5' 58W tube is spec'd at 5200lm. Change to a twin fitting, using 24W LED tubes will give the same light o-p as a single fluorescent

If however you change to a batten with a fixed LED array you can get some really good light, for ex the Sylvania Single 5ft LED Batten gives an impressive 6500lm so I'd better get back to the electrician and ask for these or equivalent. You'd need two of these to replace a twin fluorescent

The comparison between 'fluorescent' lumens and 'LED' lumens seems somewhat complex. I did once come across an explanation but didn't take sufficient notice at the time and there is now no trace of the article.
However, I replaced a 58W electromag batten (5200 lm nominal) in my kitchen a year or so ago with a Megaman Malo 42W 3000K batten whose rated output of 4500 lm appears far brighter than the original, to the extent that my wife actively dislikes the 'floodlit' effect.
I've seen a similar effect with other fittings I've replaced since then, and similar discrepancies are apparent on lighting distributors' web pages, where the figures for '5 foot equivalent' or '6 foot equivalent' don't stack up.
It seems that a correction factor of about 0.66 could usefully be considered.

[emeritus]

No experience with fluorescent replacements, but all the GLS LED replacements I have come across have markedly directional light emission characteristics, often only 180° rather than the almost 360° of a frosted a Tungsten GLS lamp. Possibly the same situation exists with fluorescent replacements and might account for different figures.

Last year the fluorescent fittings in Chelmsford Market were replaced by new LED luminaires. While the new lamps themselves seem as bright as the old ones, in the old installation, light was reflected by the white ceiling above the suspended luminaires. The new installation has a lowered ceiling, level with the new fittings, consisting of very dark panels that absorb light rather than reflecting it, giving the sort of rather oppressive effect that is described as undesirable in a 1960's textbook on electric lighting practice, but now seems to be fahionable.