How to replace butterfly tube

[GrahameS]

As per title .. can someone please explain
One of my outdoor lights (Lombard) - under the soffit -started flickering
Took off the cover/diffuser but can't see how to replace the "butterfly" tube - it's GE polylux F282D/835

The plastic fitting is very flimsy and I don't want to force and break anything.
I could order a replacement tube and see if I can figure it out from that but I don't know if it's 2 or 4 pins

 

[JohnD]

"butterfly" tube

I wonder what that is?

Could it possibly be a 2D lamp?

You grasp the plastic square in the middle and pull it off the socket.

 

[Wontdothatagain]

Ensure that the power is turned off first. Firmly pull at the center plastic fitting and if you can push at the back plate at the same time with the other hand all the better. It will just pull out.

DO NOT TRY TO LEVER IT OUT AND DO NOT PULL ON ANY PART OF THE TUBE, IT COULD SHATTER AND CUT YOUR HAND TO SHREDS

 

[Adam_151]

Ensure that the power is turned off first. Firmly pull at the center plastic fitting and if you can push at the back plate at the same time with the other hand all the better. It will just pull out.

Or if you're really unlucky the brittle lamp socket from a luminaire which has run almost 24/7 since it was installed will crumble round the edges and pull free of the gear tray....

 

[ban-all-sheds]

"butterfly" tube

I wonder what that is?

Could it possibly be a 2D lamp?

GE polylux F282D/835

BTW, Grahame - if you're struggling to find an exact match for that lamp you don't necessarily have to. The /835 will be the colour temperature (that colour is AKA 3500K and White), and the 28 will be the wattage.

You can fit a lower wattage if you like, or a different colour temperature.

 

[Adam_151]

Remeber to note how many pins it has though, 2D lamps come in 2pin and 4pin variants, with 4 pin being more common

EDIT: just noticed this:

You can fit a lower wattage if you like

The control gear will be sized to a particular wattage of tube, you can't fit a 16w 2D lamp in a 28w fitting even if it did fit

 

[ban-all-sheds]

Isn't it 2-pin for conventional ballasts, 4-pin for electronic?

 

[Adam_151]

Isn't it 2-pin for conventional ballasts, 4-pin for electronic?

I think you might be right, though I'm not 100% sure that there are not exceptions, I get the feeling that all HF ballasts require 4 pin tubes, but that fittings with magnetic chokes could be designed to take either, but dont quote me on that

 

[ban-all-sheds]

The control gear will be sized to a particular wattage of tube, you can't fit a 16w 2D lamp in a 28w fitting even if it did fit

Okaaay.

Why am I looking at a ballast now which says it can take 1 x 18W or 1 x 23W or 1 x 24W or 1 x 26W lamps?

 

[Adam_151]

Maybe because those pesky electronics designers have caught me out on that one was thinking in terms of magnetic chokes...

And you seem to have a de-bounce issue with your 'a' key...

 

[securespark]

Baaan Aaall Sheds

 

[333rocky333]

Isn't it 2-pin for conventional ballasts, 4-pin for electronic?

I think you might be right, though I'm not 100% sure that there are not exceptions, I get the feeling that all HF ballasts require 4 pin tubes, but that fittings with magnetic chokes could be designed to take either, but dont quote me on that

With the magnetic chokes the 4pin light fitting would have a seperate starter built in, this is more common with 28 watt fittings and 16watt Emergency fittings.
The 2 pin lamp has the starter built into the lamp.

If you can see the ballast then you can proberly see the back of the lampholder also
If there are 4 wires then it is 4 pin
If there are 2 wires then it is 2 pin

 

[Adam_151]

That makes good sense

never really thought about it properly before, I guess I must have just assumed the relativly short tube length of 2Ds let them be started without warming the cathode(s) if the gear was designed for it...

Now, another one for you.... is there any truth to the rumour that 2 pin tc-d lamps are going to be phased out soon?

 

[333rocky333]

There is a list about which details the phasing out over the next 10 years or so.
I dont think them lamps are on it, but in about 5 years it moves on from lamps to things like magnetic chokes and ballasts

http://www.gil-lec-energy.com/incandescent-lamp-phase-out.php

 

[Lectrician]

If it is 4 pin with a standard ballast, you will also have a standard tube starter - replace that too.

2 pin ones have 'the starter' built into the central white plastic bit.