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rmcguinness · Joined: 15 Dec 2003 Posts: 33 Location: Croydon

I have just bought 4 bathroom spots which take, up to, 50w halogen dichroic bulbs. I need to buy a transformer.....what spec should i be buying (ie 240v/65w, 240v/105w, 240v/150w, 240v/210w) ?

Sorry for being dense! Embarassed

thescruff · Moderator Joined: 03 May 2003 Posts: 4418 Location: Bath

Havn't a clue but I do like pretty coloured lights.

All mine at home are 12 or 24 v and come with its own transformer.

perhaps Alan can through some light onto it.

scruff

AlanE · Posted: Tue Dec 16, 2003 8:17 pm Post subject:

Add the wattage of each individual bulb and you need a transformer about the same. Your case 4 x 50watts = 200 so you need approximatly 200 Watt transformer.

Of those you mention you will need the 210 Watt on.

Don't be tempted to purchase one with 'a bit in reserve'. You will shorten the life of the bulbs. The transformer provides its voltage level at its rated output. If you take less current then the voltage output will rise.

Alan

thescruff · Moderator Joined: 03 May 2003 Posts: 4418 Location: Bath

Like I said and I'm probably wrong again, these fitting have individual transformers.

Within a low voltage system the volt drop is significant, Therefore the greater the distance between the transformer and the fitting the greater the necessary cable rating.

for example 200W would require a cable size 6.0mm2 over a maximum distance of 3.38 m.

50W with the same size cable would have a maximum 13.52m

other lenghts and sizes by request

scruff

AlanE · Posted: Wed Dec 17, 2003 9:05 am Post subject:

Transformer certainly needs to be quite close to light fittings. Really within a metre if possible.

Alan

rmcguinness · Joined: 15 Dec 2003 Posts: 33 Location: Croydon

Thanks gents

rmcguinness · Joined: 15 Dec 2003 Posts: 33 Location: Croydon

FYI

Following additional advice i ended up using a 200W transformer (with a single outlet). This was then connected to a lv fused splitter.

I could have used a 4x50w multi outlet transformer. The multi transformer would have been £50-60. The solution i used was 20 quid for the lot.

AlanE · Posted: Wed Feb 11, 2004 11:14 am Post subject:

Sounds a good result.

Alan