Hmm doing a bit of digging ive found someone else with this issue:
"Just thought I'd chime in with one problem I had with the FT02 that I have not heard others talk about.
I tried out a couple higher power PSU's that admittedly may be too powerful for this case, the Corsair AX1200 and the Seasonic X-1050. When in the FT02, they ran very loud, with the PSU fan running at a very high speed, even when they were using well-under 200W. I suspect this problem was due to the vertical orientation of the PSU. This position may make some PSU's think they are running much hotter than they are actually running. Perhaps this vertical position directs a lot of heat at sensors in some power supplies.
Maybe I'm overlooking something, I dunno. If those of you at SPCR feel like checking this yourselves, I welcome you to do so.
Currently I use a Corsair AX850 in my FT02 without this problem."
So it may be that this PSU dosent like vertical orientation.