Fluorescent tubes

I have 3x fluorescent lights in my garage, one 1x and one 2x. They have all gone on the blink at the same time. Is there any way I can tell whether it's the starter coil or the tube, sort of changing them out and trying?

It also seems to be quite tricky to change a tube in these units. Other units I've changed tubes in had ends which pulled back and it was really easy to change a tube. With these ones you need to rotate the tube until it unlatches, and it needs enough torque that I worry about shattering the tube. Am I missing something here - is there a simple technique?

Reply to
Simon Elliott
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Ambient temperature related?

break bear in mind that you will have finely divided mercury widely scattered and poisoning your environment. (Don't do as I did - I hoovered it up with my vacuum cleaner, and getting that repaired (in the days when one could get cleaners repaired) cost a lot more than new tubes and fixture.)

Reply to
Malcolm Stewart

"Malcolm Stewart" wrote in message news:d0v4kq$t32$ snipped-for-privacy@newsg1.svr.pol.co.uk...

How close together were the failures ?

Did they worsen progressively ?

I can understand the twin tubes failing at the same time since they are probably wired in series with a common ballast, and modern lamp manufacturer is very consistent these days, but even if installed at the same time one would expect a bit of a gap ....

I'm not sure what you could use as a release agent if the tube is sticking - I wouldn't think WD40 would hurt ...

You may well be able to pop the plastic lugs that hold the sockets onto the casing ....

Like Malcom suggests I would look for a common external factor ...

Jeremy

Reply to
brugnospamsia

Simon Elliott presented the following explanation :

It could be starter, choke, tube or even the wiring (internal or external) at fault. What do you mean by on the blink? No sign of any life at all? Actually blinking, but not staying lit?

If all died together suspect the latter.

Suspect tubes which are blackened at the ends. If the tube ends are glowing, try (if you can whilst still glowing) taking out the starters. If the tube then strikes you need to replace the starter.

If there is a notch missing in the holders, then they twist to remove. The knack is to be gentle but firm and to try turning both ways as some only will turn one way out. Even though they are twist out types, you can usually spring them out too.

Reply to
Harry Bloomfield

if you tell us the symptoms in detail. or Try in order: starter tube conncetions ballast

2nd rate design. The ends can usually be levered out a little with a scerwdriver, just enough to unstick pins from contact strips, then it rotates.

Dont apply enough force to break tubes, all that will do is break either tube or end connections, and is completely unnecessary.

NT

Reply to
bigcat

Try the starter first - only about 60p. Experience tells me that if the thube strikes with the starter out then it is probably the starter Blackened ends on the tube suggest that the tube is on the way out. If neither new tube or new starter wok then it's the ballast. Try systematically swapping tubes and starter.

Malcolm

Reply to
Malcolm Race

the tubes will not light when it gets cold

Reply to
James Salisbury

good point. Full width tubes are better than energy savers in this respect.

NT

Reply to
bigcat

Nothing to do with the cold snap?

Reply to
Dave Plowman (News)

Dave Plowman (News) wrote :-

There have been a few references to cold in this thread but at work we have twin 6' fitting that work regularly in sub zero temps with no problems ?

Regards Jeff

Reply to
Jeff

As others have said, you'll need to post more details of the exact failure mode. Also, what length and wattage are the tues?

If they all failed at the same time, I would look for a common factor, such as main voltage, control gear unsuitable for low temperature operation. Switch-start control gear on 8' tubes is notoriously bad at low temperature starting.

Tubes are stronger than you might think. I've stood on them in order to break them, and that normally won't do it (stamping on them is usually required).

Reply to
Andrew Gabriel

It depends on the type of starting arrangements.

Reply to
Dave Plowman (News)

Well , you learn something new etc .... I will keep my eye out for this effect, do you know which part doesn't like the cold ? fwiw all the ones i've had dealings with have traditional starters

Regards Jeff

Reply to
Jeff

It happens that Jeff formulated :

It is the tubes themselves which suffer from the cold temperatures and it is the control gear which has to be improved for colder starting.

Reply to
Harry Bloomfield

I had one fall on my head once, in an unlikely incident. It fell maybe

2 feet, and shattered immediately, despite landing on padded bone from 2'. Maybe it depends how its done?

NT

Reply to
bigcat

It depends on the type of control gear, specifically the open circuit voltage available. The striking voltage of tube increases as temperature decreases. For 8' tubes, it's getting near mains voltage, and the starter has difficulty detecting the difference between mains voltage, and the initial cold running voltage, and so can continue to try starting the tube when it has actually already started. If it gets even colder, the tube's cold running voltage will get too high to start at all on a series ballast circuit.

Modern electronic control gear will have no problems. In the pre-electronic control gear era, an alternate design called SRS (Semi-resonant start) also had no problem starting long tubes at low temperatures. It uses a double would ballast and an essential circuit capacitor, but no starter. When the circuit is first switched on with no arc in the tube, the capacitor and ballast 'ring' to generate twice mains voltage across the tube and the heater current. As the tube starts conducting, this kills the 'ringing' and changes the nature of the circuit such that the ballast falls back to its current limiting role. The heater current is rather low, so the tube takes around 5 seconds to come on, but it does so by gradually like a light dimmer being turned up with no flashing. A side effect of the essential circuit capacitor was the circuit when running had a power factor of 1. This was a very clever and simple ballast circuit design, but little seen in homes as it doesn't work with tubes less than 5' long (the twice mains voltage could cause them to instant start in cold-cathode mode, rapidly wearing them out).

Reply to
Andrew Gabriel

It sometimes gets pretty cold. I didn't realise this is an issue, as Other units in other houses seemed to work better when cold.

This did indeed happen after some electrical work elsewhere in the house which tripped the RCBs a couple of times.

The single unit is just dead. The double unit sometimes gives a low buzzing with the ends of the tubes glowing.

Reply to
Simon Elliott

They failed within a few days of each other, after some electrical work elsewhere in the house.

I've seen one broken when a kid threw an empty coke can at another kid and misjudged the trajectory...

Reply to
Simon Elliott

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