Hi, Thanks for the quick reply. The dimmer is not essential, but would be nice to dial back the brightness of the sign. I was thinking of just buying a dimmer, but as you say 3kW is a lot for it to handle. It is only for indoor use as well.
Another question, which is completely elementary but, looking at the sign I linked, If the power cable runs behind one of the support beams as it reaches each letter the cable should be split (Suggested splitters?) to supply the individual bulbs. The cable then running behind the letters should be able to be a lot thinner, (more 1mm). Is this correct? or should I be safe and use the 2.05mm that would be used for the main trunk of the supply.