Geoff, No noise, electrical or audible, evident from my 'Sunny Boy 4000TL' inverter fed by 16 x Sanyo HIT-H250E01. 73 Tom G3OLB G4AFJ wrote: <I guess some of you will have experience of these systems. Looking at the possibility of an installation and don't want any qrm generating devices. Any info good or bad appreciated.>