An alternative idea is to use a metal box with 20mm knockouts at both
ends. This would be fitted in the cavity (screwed down) and use a
gland to terminate the SWA cable with the conductors going into a 30A
terminal block. 6mm^2 T&E would continue from there into the CU.

Has anyone had to deal with a similar situation, and come up with a
neat solution?


I did something similar recently on a garage and I used an
outdoors/waterproof MK one gang socket (I had one spare) to terminate the
SWA. As the supply to the garage was fed from the house CU by a 40 amp MCB I
changed the socket for a 45 amp DP switch and used the round knockouts on
the MK backbox to terminate the incoming SWA. The switch is now an isolator
for the garage CU.

Adam