Branch circuit?

I'm working on selecting fuses for a control circuit. My source is

460/3/60, going to a 300 VA transformer, to a fuse, a switch, then to a motor starter.

Would this be considered a "branch circuit"?

I would like to use a time delay midget fuse, using the fuseholder mounts that come on the transformer. However, the specs on the midget fuse say "not designed for branch circuit use".

Thanks.