From SANS 10142 SS 6.8.2.3:
Any deviation from the convention of connecting line to the top and load to
the bottom of switchgear is not recommended. Reverse connection is
allowed only if
a) it is specifically allowed by the manufacturer,
b) “load” and “line” are so marked that they are clearly visible during
maintenance, and
c) any contradictory marking is not visible after installation.
A grid-tied inverter is a “load” in this case, since it should behave as one - ie when grid is off, it is off.