8ft flourescent tube wierdness...

[MattChan]

We recently had one or two of the 8ft fluorescent tube in our warehouse fail. So we ordered up some replacements from TLC Direct but when we fitted them they failed to light, there was faint illumination at each end but thats it.

We then bought some from a local wholesaler and had exactly the same problem.

What seems strange to us is that if you move a working bulb from another light fitting into the place where the new one fails to work it illuminates fine!

So have we bought two dodgy batches of bulbs or has another part of the fitting failed in a way that only old bulbs (with the same part number as the new ones) will work?

 

[simon_m]

Sounds like you need new starters. Small round thing on the side of the light, twist it anti clockwise to remove put the new one in and twist clockwise to lock it in place.

 

[dannyboi2003]

How old are the fittings?

As simon has already suggested you probably need new starters or depending on the age of the fitting they may have old choke ballasts, easiest way to know is when you turn the lights on do they make a loud buzzing noise?

If they do then the choke ballast has probably failed and requires replacing, however these are no longer available so newer switch-start gear will need to be installed in its place.

I doubt very much that the lamps are faulty.

All the best
Dan

 

[johno12345]

There are 2 different 8ft tubes available, 100W and 125W. The 125W tubes are unlikely to work in a modern fitting. Also check the starter is rated for the 100W tubes as most only go to 80W. Do the new tubes work in the old fittings?

 

[Steve]

Are there many 8 foot fittings in use? We have 3 in our warehouse. There used to be 4. I suspect what happened was the relamper came, didn't have any 8 foot tubes, and replaced the fitting with a HF 6 foot one instead of making a return visit. One started flickering the other day, so they sent an electrician, who didnt have any 8 foots, or new fittings! He had to make a return trip (They sent an electrician, since we had an electrical fault elsewhere too)

 

[RF Lighting]

There are 2 different 8ft tubes available, 100W and 125W.

Don't forget 85W

 

[Pensdown]

Well, that's two things I've learnt tonight, 85watt 8ft tubes (although I can't anyone that stocks them) and this - which may answer Steve's question

Philips announces that it will stop supplying 8ft tubes

In a world that is increasingly concerned with protecting the environment and reducing the waste of our energy resources, Philips, one of the world's leaders in technology and sustainability programs, has stopped the supply of its 8ft fluorescent lamps.

The lamps were introduced decades ago and have since fallen behind the latest developments in lighting improvements. They require many times the mercury content as the most modern MASTER fluorescent lamps from Philips, and they use old fashion conventional gear that wastes energy, reduces light output and will soon become obsolete.

And further, maintenance costs are high as they often require 2 persons to replace a single lamp. Disposal becomes difficult.

With fewer and fewer suppliers producing them the price of 8fts will soon be significantly higher than that of better alternatives.

 

[shortcircuit48]

Nusku

You did fit the starters?

 

[333rocky333]

Most old 8 foots had a CAPACITOR in series with the choke .

When this goes it usually stops it striking, but the fitting will still work the lamp ok once struck.

you can sometimes test it by charging it up with a megger
,
The rating is stamped on it.

Usually it is a 7.2 micro farad but is 440volt rated NOT 240volt
or 8.4 on some newer ones

chokes and caps available from BERNLITE based at watford.
But are now being phased out, as previous posts said, but this was first said about ten years ago due to H/S and EEC harmony .

 

[333rocky333]

Also check the wattage stamped on the choke is same as your new lamp.
Old lamps may have been already wrong size
BG fs 125 starters will work 100w and 125w tubes

 

[seasickstevie]

And further, maintenance costs are high as they often require 2 persons to replace a single lamp. Disposal becomes difficult

Been replacing 8ft tubes for 35 years. Never needed a second pair of hands so far!

The world's gone mad

 

[ericmark]

8 ft tubes are not the only length to have many different versions which will physical fit. As well as different wattage some tubes require an earth strip built into the tube. Also different diameters.

Even when everything is correct 8ft tubes sometimes fail it too cold and most need the full 240v to strike so with 230v now being the standard there have been many problems.

Most people have changed to 6ft or 5ft and used HF versions but even then there are many tubes. Some have a built in reflective surface and the same length fitting can give light outputs three times higher or lower than other versions.

The same applies to starters although it may say it will work I have found to be sure has to be right part number got caught out with fly killers took ages to find out although RS said there were the same they were not.

And a tube can cost nearly as much as a fitting
These want £21.73 for the tube

 

[ColJack]

the only extra pair of hands we ever needed was somone to foot the ladder and take the old tube off you and pass you the new one...
but gone are the days of a tripple extension ladder and hanging on with your knees while you tried to get an 8ft tube into a burnt and crispy end cap...
now you do it form mobile access platforms and swap any fitting that starts to look remotely tanned...

 

[ColJack]

I've never yet seen 230V in an environment where 8ft tubes are fitted..
it's normally factories and they have their own sub, and it's 250V all over the installation..

it may say 230V on the sticker, but if you got 230V at your supply, I'd get onto the suppliers...