Fuse size?

[macson66]

Hi all, I'm a newbie so apologies for a rather simple question. I'm looking to build a TPA3255/LRS350-48 amp but am struggling on the fuse size on the 240v power input side - I know the output is 48v/7.7amps but don't know how to work out the 240v side for the fuse? Sorry if it's a bit basic but I'm not sure how many watts on that side (600w ??). Thanks.

 

[FauxFrench]

2A slow blow (T).
Max output power 48Vx7.3A=350W. 10% add-on to include SMPS losses. That makes 385W. With some margin and the next fuse standard value (2A). 240Vx2A= 480W

 

[Osvaldo de Banfield]

If you are using a new SMPSU, the fuse is inside the SMPSU itself. If you are using a trafo plus rectifier, use almost 3 or 4 times if no inrush limiter and 2 as said below if there is any inrush current limiter.

 

[macson66]

Thank you both.