"Paul" wrote in message
...

hi its part number is FLCR630501F there is a diagram here of the filter
under FLCR,
http://www.worldproducts.com/pdfs/WPIISF.pdf
looking at the diagram it does appear that the U pins are the unfiltered
supply.

My vote would be that L and N are line in and U/U are line out to the
apparatus.

N