I did see some data on this a few years ago, but I can't remember the details now. I certinly always make the fuse on the primary an anti-surge or "slow-blow" type, otherwise it needs to be so much larger that close overload protection is lost.
A while back I used a 500VA toroidal xfmr to step-down from 240V to 120V to run imported U.S. equipment. I never measured the in-rush current, but just turning it on with no load made the lights dim momentarily, and they were on a different branch circuit, so the surge must have been quite high.
[This message has been edited by pauluk (edited 10-05-2001).]
