MOV selection guidance needed

[satiz]

Hi,

I need to select MOV and input fuse for my SMPS circuit, Please give me some guidance. My specifications are given below

AC input max : 275 V
Rms current : 250mA
Circuit having 5KVA isolation between input and output sections

 

[d123]

Hi,

For the varistor, it needs to be selected to have a trigger voltage above the required load/SMPS voltage and at or below the required clamping voltage, the current ratings are usually higher than 250mA.

Try browsing this product page for Varistors at Panasonic to look for what you need.

For a suitable fuse, this might help: Fuse Selection Guide

Don't know if you've seen this, about protecting the MOV too: Designing with Thermally Protected TMOV Varistors in SPD and AC Line Applications