If the current rating is adequate class cc fuses are code compliant. Personally, I would use transformer fuses on the line side. FNQ-R fuses are class cc fuses but have a different tc characteristic so they are better suited for the line side of a xfmrs than an LPCC fuse. You could also use any other branch circuit rated fuse such as a class j.
LP-CC fuses were developed
from the FNQ-R in order to better handle motor starting current. They are more expensive than FNQ-R and since the load is a transformer, I wouldn't waste the money on them. Class J are "better" if you have sensitive equipment, but are even MORE expensive and unnecessary for transformers. Yes, you CAN use them, but again, kind of a waste of money in this application. FNQ-R (or an equivalent from another brand) are the optimum choice for small transformer primaries.
A word of caution here. These fuses are the same physical dimensions of other "midget" fuses, but many of those are NOT listed as "Branch" protection, meaning they must be used as "supplementary" devices behind OTHER branch protective devices. People often assume that if they fit, they can be used. Not so. The fuse must say Class CC to be used as a branch device.
