How could you get "the fan trigger, fan live an N through the FCU"? At best, only one of the two L's would be fused.About the only way round it that I can see is to use a DP light switch, one pole switching the light and the other pole switching the fan trigger. The light not via the FCU, and the fan trigger, fan live and N through the FCU.
The fan live, and N are direct from the FCU.
The fan trigger is from the FCU through one pole of the DP switch.
The light live and N are direct from the lighting circuit and not through the FCU.
[code:1] +------------------------------------------------------+
| |
N FAN |
LIGHT SL PL N--------------------------------+ |
L | | | |
| | +---------fan perm live---------+ | |
| | | | |
| | | | |
| | | | |
| +-----SW1a-------------------------+ | |
| | | |
+-------------SW1b--+ L N |
| +-------+ |
| | load | |
| | FCU | |
| | supply| |
| +-+---+-+ |
| | | |
+----------------------+ | |
| | |
L N |
| | |
| | |
| +-------+
| |
v v[/code:1]