Expertis on selecting a fluorescent electronic ballast?

[dom]

I have a bunch of Eglo Giron light fittings. These use a 22W circular T5c fluorescent lamps.

For complicated reasons I now have 6 units with no ballasts.

All the other units, with the original electronic ballast, light instantly on switch-on (but don't like the cold, below 17c they can be reluctant to light).

I've tried replacement electronic ballasts (manufacturer's spec includes T5C) from Tridonic and b,a,g - and get the same behaviour from both - they will always light regardless of temperature, but after a second or so's pause from switch-on.

Of course I want the best of both worlds - instant-on regardless of temperature.

Is there an underlying issue here with how ballasts work? Is this something to do with preheat/no-preheat?

[dom]

To answer my own question (after a bit of googling):

[Brian Gaff]

I think it has to be preheat issues as I had a normal tube, well a double tube like this some years ago, it was very lightweight so obviously had a solid state ballast and it would not light in my shed in winter, it flashed a bit and then gave up and sulked. Brian

[meow2222]

switch-on (but don't like the cold, below 17c they can be reluctant to light).

from Tridonic and b,a,g - and get the same behaviour from both - they will always light regardless of temperature, but after a second or so's pause from switch-on.

do with preheat/no-preheat?

Instant-on is very hard on tubes, and is best avoided

20w CFL ballasts may do the job.

NT

[Andrew Gabriel]

switch-on (but don't like the cold, below 17c they can be reluctant to light).

from Tridonic and b,a,g - and get the same behaviour from both - they will always light regardless of temperature, but after a second or so's pause from switch-on.

do with preheat/no-preheat?

It has become impossible to find instant start electronic ballasts over the last few years. The nearest you will find is the Philips Matchbox Blue series - blue 124 LH model should be right for that tube. RS parts 397-0277 and 397-0261 (they're just different shapes of the same thing). They can also be found on ebay sometimes (and there are also versions of the above two available without any case - just the PCB).

When the Blue series originally came out, it was truely instant start. Now it has a very short pre-heat. (The red series is the proper preheat version.)

[fred]

In article , Andrew Gabriel writes

They're showing discontinued at RS I'm afraid, don't know about elsewhere, they look good and reasonably priced. The suggested replacements appear to be from BCC and there's no mention of ignition time in their data (0.1s on the ones you mentioned).

[meow2222]

Most CFL ballasts are instant on.

NT

[dom]

Thanks for everyone's feedback here.

I think it's best, in my application, to go for programmed-start rather tha= n instant-start ballasts.

I bought a b,a,g, electronic ballast for =A36 to evaluate, and that seems t= o be the better choice for tube life and cold starting. Instant-start looks nice, but isn't handling colder conditions, and I had a= nother early tube failure last night. So I've approached the supplier for a price on 25 of these b,a,g, prog-star= t ballast units.

Incidentally, I've also looked at dimmable ballasts. Too expensive right no= w, but on future projects I would look at making provision in the wiring fo= r them.