Shower room extractor fan

[bluemartin]

I am installing low voltage selv fan in ensuite showeroom. Low voltage appropriate lighting already in place. Light switch external to showeroom. Wiring for lights and proposed fan in loft above. Can I connect junction box and spur off loop in supply cable which feeds the lights to give a switched supply to fused connection unit - then link to shower transformer and then fan itself. The fan has no timer and would otherwise require pullcord. Propose wiring 1.5 twin and earth exclude earth connection.
Any pointers appreciated.

 

[ban-all-sheds]

Can I connect junction box and spur off loop in supply cable which feeds the lights to give a switched supply to fused connection unit

You can, but that won't get you a switched supply, the loop is permanently live.

You can put a JB in the cable carrying the switched supply to the lights though, or to cut down on unnecessary joints connect the fan supply cable to the lighting transformer supply terminals if they have the capacity.

Are you aware that this is notifiable?

 

[bluemartin]

Thanks for that ban-all-sheds.
I was planning to put junction box where you suggest.