I am putting RGB LED strip lights in a room, powered by a fairly heavy duty (30A) 12V transformer.
The transformer will also power a Raspberry Pi (volatage will be split to give it 5V)that will be used with a touchscreen to control light colour and function, and a motorised blind. There will also be a relay from the Pi controlling a couple of normal (mains) lights.
Given the "primary function" of the transformer is for lighting, I assume it should be on the lighting ring. (I guess the risk is with "forgetting" the motor etc is on the lighting ring.) Even though there is a high current draw at 12V, it is only 1.5A at 240V. There are only a couple of other lights on this circuit, so I think 1mm2 cable will be fine too.
Is this approach correct?
Best Answer
Basically, yes.
1mm2 twin and earth cable (I presume that is what you are proposing) could carry up to 16A, depending on where it runs, so 1.5A is well within the headroom (assuming that you aren't talking such long runs that voltage drop becomes an issue).
For lighting, however, I tend to use 1.5mm2 in preference to cable 1mm2.