Do you have a question about the LEM PROCON PLUS 400P and is the answer not in the manual?
Connect the amplifier to the mains socket, ensuring proper grounding and matching voltage.
Switch amplifier on after other equipment, and off before others, with gain at minimum.
Use balanced signal cables for mixer to amplifier, power cables for amplifier to loudspeakers.
Never open the amplifier; contact service for repairs to avoid electric shock risk.
Input gain potentiometers to adjust signal level, variable from fully closed to nominal.