.acu files must be AutoChart Live files. I only have AutoChart Pro on the computer. My zeroline cards do not have a single .acu file on them.
So, as I mentioned before, I don't know of a way to just copy a map from one ZLC to another, at least not the map generated from AutoChart Pro.
AutoChart Live map must be an .acu file, which must have the ability to be copied from one card to another.