Twin florescent led tubes confusion

Tile seller · Aug 20, 2017

Hi vortigern,
Yes, the wiring is originally for old fluro tubes and I believe this is called retro fit.
I'll look up about led battens!
I can well understand what u mean about combos of wiring for old tubes and thus the probibily of faliure in exchanging for led.

Tile seller · Aug 20, 2017

Hi vortigern,
Yes, the wiring is originally for old fluro tubes and I believe this is called retro fit.
I'll look up about led battens!
I can well understand what u mean about combos of wiring for old tubes and thus the probibily of faliure in exchanging for led.

Toneyz · Aug 20, 2017

telectrix said:
the LED tubes tah i ve fitted all have L to pins at one end and N to the other. just reconfigure the tub wiring with wagos and ditch all the old crap.

This is how I've wired up LED tubes loads of times.

Sparkgap · Aug 21, 2017

Vortigern said:
Sounds like retro fit tubes. So originally you had a normal tube and ballast and possibly starter. The retro fit led tubes are complete rubbish in my opinion and the combinations of possibilities of wiring and failure are massive. If you're not careful I will upload a chart detailing this! Anyway the best thing to do is get LED battens and have done with it. You will never have to "doctor" anything and it is failsafe.

A lot of the retrofit LED tubes have a shorting link to replace the starter and keep the ballast so you still have some losses through that if you were hoping to save a load of money. And if you've got HF or some of the old vivatronic gear it's a non 'starter'

The Ghost · Aug 21, 2017

Well anyway LED battens, real good no fecking about. Plus you can get away with a lot less of them due to better lumen output. As a for instance...

[ElectriciansForums.net] Twin florescent led tubes confusion

MJPD29 · Aug 21, 2017

The led tubes that do not use the original ballast or capacitor are generally better in my opinion if you use them instead, just require l and n to either end of the tube from memory

Marvo · Aug 23, 2017

The LED retrofit T8 tubes we've used in the past have a solid link between the pins on one side and L+N connect to the pins on the other side.

If you replace the starter with a fuse and bypass the ballast then the wiring ends up such that the tube can be installed in either direction without going bang.

Marvo · Aug 23, 2017

You get a fuse which is the same form factor as the starter by the way....

Starter Fuse; Replace Fluorescent Tube Light for LED T8 Lamp Lightbulb | eBay - http://www.ebay.co.uk/itm/Starter-Fuse-Replace-Fluorescent-Tube-Light-for-LED-T8-Lamp-Lightbulb-/331542963577

fertom · Aug 23, 2017

Yeah for now led tubes are really cheap. We don't have to bother about ballast in leds and you have nice place to apply some automation systems

brianmoooore · Aug 27, 2017

Just fitted a batch of 1500mm T8 LED tubes into existing fittings and new LED fittings.
The LED tubes have L and N to the two pins at one end of the tube. Pins at other end have NC.
When fitted into existing fittings, starter is replaced by LED 'starter', which is just a 1A fast blow fuse presumably to blow if someone ever refits a fluorescent tube.
The new fittings have nothing inside of them whatsoever, except the two lamp holders. L and N are wired directly to one lampholder, and the other one has no connections - just there to support the tube.

Marvo · Aug 28, 2017

brianmoooore said:
Just fitted a batch of 1500mm T8 LED tubes into existing fittings and new LED fittings.
The LED tubes have L and N to the two pins at one end of the tube. Pins at other end have NC.
When fitted into existing fittings, starter is replaced by LED 'starter', which is just a 1A fast blow fuse presumably to blow if someone ever refits a fluorescent tube.
The new fittings have nothing inside of them whatsoever, except the two lamp holders. L and N are wired directly to one lampholder, and the other one has no connections - just there to support the tube.

The tubes you describe wire as per the diagram in post #22. As long as you fit the fuse where the starter originally was then the tube can be safely inserted either way around. If you remove the starter, don't fit the fuse and just wire the L+N to the lampholder on one side of the tube then there will be short circuit fault if anyone ever fits a tube the wrong way around.

brianmoooore · Aug 28, 2017

The dedicated LED fittings I fitted don't have anywhere to fit a 'starter', and aren't fitted with a ballast either.
L and N are to one end of the tube, so it has to be fitted the correct way around for the fitting to work. There has to be some kind of continuity between the pins at the other end for the same tube to work when retrofitted into old fittings, but it's not a simple shorting link. An ordinary test meter, on resistance range, gives a reading that starts at a couple of ohms and eventually reaches around 40 ohms before stabilizing.
If someone fitted a fluorescent tube to one of the dedicated fittings, it would place 230 volts across the heater at one end of the tube, which I assume would have a bright, but brief, existence.