Going to replace extractor fan that's stopped working with a new one. They are both overrun fans and the old one currently has a 3 pole isolator switch outside the bathroom with L1, L2 and N connections all used. Looking at this fan on the fantronix website (Classic White 100mm 4" dia) but in the 'how is it wired' section it states 'Permanent Live connection to L & Neutral connection to N'. Is this fan suitable for the job or will there be more wires than I know what to do with? I thought an overrun fan had a switched & permanent live & neutral. Thanks