Timers for lighting

[topc]

Hi,
I'm setting up a tank for the first time. I want my fluorescent lights (a twin D&D T5 2*39 watts thing) switched on and off automatically.

So I bought a timer plug at my DIY store. Great, except that it says that it isn't suitable for fluorescents. None of the other timers on sale are either.

If I use this will it damage my lights (expensive mistake!) or the timer or does anyone know of a timer that is suitable for use with Fluorescents?

Many thanks,

Martin.

 

[platypus]

I got my timer from my LFS.. so presumably this is safe to use with aquarium lights! Well you'd think so... although knowing my LFS you can't be too sure!

 

[CFC]

Strange the timers i use are just very cheap dial operated ones from the local hardware shop and they work just fine, the timing goes out by about 15 minutes a month but thats no hardship and my tubes all work fine, does it say why they dont work?

 

[EddieW]

It's all to do with the type of load a fluorescent draws on switch on. A standard cheap timer will generally be rated at about 13A for resistive loads and 2A for inductive loads. I believe that a standard magnetic ballast for fluorescents would count as an inductive load.

However at 240V (UK) and 2A you would need to have almost 500W of lighting on the timer to cause a problem.

I have three timers - two at home and one at work. The work one is the smallest and cheapest and is where I got the figures for load rating. At home I have slightly larger ones - on one timer I have 2 x 30W fluorescents, on the other I have 1 x 15w pygmy bulb, 1 15w fluoresecnt and 2 x 36W PC fluorescent. I have had no problems at all with the timers.

For all those using timers in the UK - don't forget the clocks go back overnight on the 25th/26th October......

HTH, Eddie

 

[Lateral Line]

Never had any trouble with the cheap dial timers either. Is it mechanical like the things we are talking about or electronic?

Inductive loads can produce voltage spikes which unless huge, are pretty harmless to mechanical switch gear, (it can arc and pit the contacts but it takes ages for this to be a big problem). The same spikes can rapidly break down a triac or thyristor in an all electronic switch.

 

[Losi]

I use cheap ones with the dials on too (3 for £8!) they work fine and have been for a couple of years now!!

 

[topc]

Many thanks for your replies. I'll give it a go and hope for the best!

Martin

 

[Alien Anna]

If you live in UK, Argos have a great deal on timers.