Studer Solsafe concept Application Note page 16

Here are added onto the middle bar the ENS31 relay's K10.1 and
K10.2 and on the bottom bar the ENS31 fuse holder's F16, F17
and F18.
It makes sense to put ENS31 before placing K10.1 and K10.2 to
adjust the height of the central bar. Then, remove the ENS31 to
facilitate wiring K10.1 and K10.2 and remplace it.
Finally, connect the ENS31 with particular attention to the order of
phases
Note that the neutral must be connected to the ENS31 otherwise
the unit may be damaged. (All references for the ENS31 are in its
user manual.)
Appendices – Page 8 / 9
Application Note 003