Now following problem arises: How to limit short circuit current to 75A? Unfortunately...

Why bugger with a transzorb? use a crowbar.

For this I just grabbed at random the 25RIA120-ND
http://www.irf.com/product-i.../25ria.pdf which is a 25A SCR. According to the datasheet it can handle 440 A for short periods. This should be enough to handle shorting the 220V (wiring inductance, fuse resistance etc will limit the current) and, if not, use twice the size of SCR. Thus the SCR crowbar is about the most robust protection you can have.

Erik