We have never had these in the US.  What is the lumen rating of these, and what would it do in a fixture for 20 watts ?

i have seen these in in signs. like for entrance for fast food places. i have seen them in light bulb depot the other day. i know that they run on 800 MA current so there about twice the brightness of F20 lamps
so i am going to eperiment with that tube if i can get ahold of them.

The European 2'40W are rated for 550mA (so two in series preheat circuit on a 50W MV ballast)

The European 2'40W are rated for 550mA (so two in series preheat circuit on a 50W MV ballast)

According my information these 40W lamps are rated 0.88A! I had a ballast from a Aeroform latern which had these specs!

Quote from: Medved on February 28, 2012, 02:36:16 AM

The European 2'40W are rated for 550mA (so two in series preheat circuit on a 50W MV ballast)

According my information these 40W lamps are rated 0.88A! I had a ballast from a Aeroform latern which had these specs!

My own notes (don't remember from where) also say 0.88 A (47 V).

The american HO lamps that have the RDC base those lamp runs at 800mA. they used a plunger syle socket
like the american single pin slimeline intstant start tubes.

I was referring to the 40 watt T12 lamps that are bi pin like out 20 watt ones. What would they do ( if anything) in a 20 watt preheat fixture?

I was referring to the 40 watt T12 lamps that are bi pin like out 20 watt ones. What would they do ( if anything) in a 20 watt preheat fixture?

The starter would have hard time igniting them, because the preheat current of the 20W ballast would be too low for the 40-watter.

Yeah I mean the same one T12 lamp with bi pin G13. I still have some of these like the Philips TL-AK 40W/33. They are 590mm long, same as a normal 18/20 W tube. There are only two type of ballasts that we used in our luminaires, a thermoswitch one known as Perfektstart for 2x 40W in series and a single lamp switchstart ballast for use with universal starter like the St111 or S10. So these tubes were running at ca. 0.88A/ 45V.

A 2 feet TL40W is also called TL-K 40W in Philips naming convention. Lamp current is 0.86A.
The letter K stands for "kracht" which is the Dutch word for power. The reason for naming it K is that these lamps are overpowered/overdriven which results in powerful light output given the lamp's smaller size.

Philips still manufactures the UVA version of the TL-K 40W: TL-K 40W/10

http://www.ecat.lighting.philips.com/l/lamps/uv/fluorescent-medical/uva-puva-tl/928004101012_eu/

There are also other varieties of the K version: E.g TLDK 30W which has the same length as the TLD15W.

I wonder if there were also the versions on the market called TL-K40W/33, 29, or 32? Does someone has some informations about the Philips lamps?

I only know the TL-AK 40W/33 with a external starterstrip whitout conections to the pin. These are the only ones which were used back then here for streetlighting.

I have a PHILIPS catalogue from 1974 which details 2ft 40W (MCFEK/TLK) lamps being available in /29, /35 and /33. There are still some (Sylvania or GE) used on London's Underground system in a few stations still equipped with T12 luminaires! It is believed these tubes are made to special order only now due to decreased demand.

Thanks! The last time I saw them listed in a catalogue from GE was in 2007. Since then this type of lamps disappeared. Are you sure they are still made?

Of course you could place an order of 10000 TL-AK 40W/33 but they would be beyond the price.