Combi Boiler Cable for outdoor lights

[RF Lighting]

Fair do.

I agree an RCD is a must in this situation if a socket is used.

I was refering to a supply for fixed (non socket connection) lighting, wich does not require RCD protection.

0.4s disconnection can usually be met with just an MCB providing the EFLI for the circuit is within the accepted values.

I think an external socket would be a nice thing to have. Quite convenient for other appliances too

 

[ban-all-sheds]

if I don't use the trailing socket but cut plugs off transformers and use a suitable amperage connection box with suitable cable and protection from the larger IP65 box back to the smaller IP65 connection box, does this then mean no RCD required?

Yup - no socket, no RCD required.

But if you can cut the plugs off (i.e. they aren't wall-warts) you've then got the fuse problem multiplied 3 times - those plugs would have had (probably) 3A fuses in them, and neither the cables, nor the internals of the supplies, will be rated for the 20A MCB.