Nilfisk ADVANCE POSEIDON VL500 Séries Mode D'emploi page 11

Only applicable to UK.
Blue-neutral brown-live
12
TO CONNECT THE NEW PLUG:
If using a three-pin plug, do not make any connection to the the termi-
nal in the plug which is marked with the letter 'E' or by the safety earth
symbol or coloured green or green & yellow. This machine is double-
insulated and no earth connection is necessary.
The blue wire must be connected to the terminal in the plug which is
marked with the letter 'N' or is coloured black or blue.
The brown wire which must be connected to the terminal in the plug
which is marked with the letter 'L' or is coloured red or brown.
If the plug to be fitted does not conform to the above notation then con-
sult a qualified electrician.
Original instruction