I guess it makes economic sense to do so now that the tube has blown.
I have partially dismantled the existing fitting.
Do these things have standard mounting holes so that a new batten fitting would slot into place?
The old one probably dates back a few decades.
Also, why on earth are there no less than four twin-core and earth cables coming out of the ceiling?
(All the cores are wired together in terminal blocks wrapped in tape. Looks like a bit of a bodge job).
Usually. Some are designed as straight drop in replacements. Others will require some wiring changes to the fitting to take the old magnetic ballast out of circuit. Follow the instructions with your lamp carefully.
You would normally expect at least 3, however it may be you have a branch in the circuit at that point, with a feed to an additional lamp being taken from the position.
See here for an illustration:
(you may have more than one "Supply cable to next light fitting")
I'm planning to replace the *fitting*...
Thanks. There's no other light fittings on the same switch *now* but there may have been in the dim & distant.
ah, ok misread that. That should be easy enough, but the screw holes etc are less likely to match!
The cable out is not necessarily to an additional lamp on the same switch (although that is a possibility), but is usually the power feed to the next lamp - which will probably be in a different room. (i.e. the circuit starts at the consumer unit and runs to the first lamp, then daisy chains to the next one in the next room. The last lamp fitting on the circuit will not have a feed out - so there would usually just be two cables on that - power in and a drop to the switch).
Ah, gotcha, although in this case I'd expect it to go on to the other light fitting in the kitchen - no sign of a branch, but there may have been one originally. But four is only one more than "normal" so I can rest easy.
There's no guarantee that a new fitting will use the same mounting holes as the existing. I think that's what you mean. If you just replace the tube you will have to remove the starter (Little thing that sticks out at the side. Just twist it to remove.) from the fitting. Some LED tubes require a dummy starter but that should be supplied if required.
But does it? Fluorescents are vastly more efficient than tungsten. And have a longer life too. So any savings in running costs not the same sort of percentage. You'd need to do careful sums, given LEDs cost more.
What was there before? Maybe it was some form of multiple light fitting. Brian
I have two Thorne fittings here one double one single unit and was wondering the same. Both have now started to buzz, one assumes from the ballast choke. Not having had experience of replacing with led, does one just take the capacitor, choke and starter out and wire up one pin or both to the mains input or what? I'd be loathe to remove the fittings as the next thing will be the ceiling will need to be redone with paint!
Brian
Sometimes buzz is caused by a bad tube partly rectifying the power. If the cause is the ballast, take hammer & nail to the edges of the ballast laminations, or varnish it. In the unlikely event those fail, mount the ballast on rubber washers.
NT
It doesn't *have* to daisy-chain, lighting circuits are radial circuits so branching is perfectly valid. In that case, one cable will be the switch drop, one will carry unswitched power from the previous light or the consumer unit, and the other two will carry unswitched power to two other light fittings - either or both of which may have more fittings beyond them.
Mike
That depends, Aldi were flogging off 5' 20 W 2000 lm LED "tubes" for £4.99... Roughly half the lumens of a 5' 58 W florry but as our eyes are log not lin the reduced level isn't really noticeable. Put it this way there has been no adverse comment from SWMBO'd, mind you I'm not sure she has noticed the instant start rather than the several second preheat of the traditional florry.
These LED tubes are direct replacement for a florry tube and are supplied with a dummy starter. I suspect that leaving a standard starter in would kill the tube when it tries to strike it...
Not actually sure why they need a dummy starter. Is it just to get power to one end of the tube for the LED driver?
Well half the lumens are not going upwards and getting wasted!
The dummy starter is to get L&N at one end, well actually either end, so that the LED tube can be fitted either way around and still work (one end of the LED tube is a short).
Leaving in the original starter will not kill the LED.
ill work
Surely a good DIY person would want to remove redundent chokes. ballasts and capacitors and make the wiring suitable for purpose. All this Dummy Starter seems a bodge to me.
In our old house I fitted electronic starters 20 odd years ago. Virtually instant start with no noticeable delay and no failures!
Damn! Should have rescued them before we moved! On the other hand, if I replace them with LEDs when the current tubes die, I won't need them, will I?
A decent electronic ballast starts a florry pretty well as quickly as a main LED.
Electronic starter or electronic ballast? Our florries have lumps of iron ballasts but electronic starters, they have a good second or two preheat before striking, first time, everytime. Electronic ballast for the fish tank lights also delays before striking. I was under the impression that striking a florry before the filaments were hot wasn't a Good Idea, mind you they probably get hot enough within 1/2 a second.
Indeed.
As the most common LED tube sold in the UK is shorted at one end and has the driver at the other end then it makes sense to wire the fitting to suit that and make sure that the lamp will work either way around without causing the MCB to go bang.
And still wastes half the tubes output onto the light fitting.
only if the back is painted matt black. In the case of the one I have in my kitchen the back is white and reflects the light into the room.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.