The ground and neutral connections are all tied together through
the printed circuit board as shown in the schematic 17B. The hot
(Line) wire does not link with the other L terminals until after it
passes through the main fuse F3.
Main power is terminated on the bottom rung of the Power block
marked IN in figure 17C.
See section
6.3.5 Power In and Relay Output Termination
Figure 17C Relays R1, R2 and the Power block