IEC connector with fuse and switch

If your fuse comes with a ➡️ marking (like QSA fuses) which are the latest rage in aftermarket fuses. If the fuse you’re trying don’t have any orientation marking, then experiment with both sides!

Thanks to @willgolf for posting below explanation on a QSA thread.

“It depends on the orientation of the iec input on the back of the component. if the iec input is oriented so that the center contact is below the contacts on the left and right, then the hot is on the right side, and the arrow should point to the left. If the center contact is above the left and right contacts, then the fuse should point to the right".

THANK YOU

Yes, thank you willgolf! That is indeed the direction they have gone on mine, as determined by listening.

SO, on my amp(PASS Labs x250.8), the center contact is oriented to the LEFT and the fuse points in/out, NOT UP/DOWN....any thoughts?

“if the iec input is oriented so that the center contact is below the contacts on the left and right, then the hot is on the right side, and the arrow should point to the left”
@jw944ts, 

Going by the advise from TweekGeek, you would insert the QSA fuse with arrow ⬆️ pointing towards XLR/RCA inputs. 
https://www.tweekgeek.com/quantum-science-audio-5-x-20mm-slow-blow-fuse-limited-availability/