Mitsubishi Electric FR-A8NC Instruction Manual page 13

 Installing the option
(1) For the two mounting holes (as shown in the next page)
that will not be tightened with mounting screws, insert
spacers.
(2) Fit the connector of the plug-in option to the guide of the
connector on the inverter unit side, and insert the plug-in
option as far as it goes. (Insert it to the inverter option
connector 1.)
(3) Fit the one location on the left of the earth plate (as shown
in the next page) securely to the inverter unit by screwing
in the supplied mounting screw. (tightening torque 0.33
N·m to 0.40 N·m)
(4) Fit the one location on the left of the plug-in option
securely to the inverter unit and the right of the plug-in
option to the inverter unit together with the earth plate by
screwing in the supplied mounting screws. (tightening
torque 0.33 N·m to 0.40 N·m) If the screw holes do not
line up, the connector may not be inserted deep enough.
Check the connector.
12
INSTALLATION
Spacer
Earth plate
Inverter side
option connector
Spacer