Backup of library HD

I made a clone of my library HD as suggested by forum members using Carbon Copy Cloner. Now I am hesitant to use Time Machine on my iMac for fear of backing up to the wrong HD. I normally use Time Machine to back up my computer's main HD.

There is no indication as there is on CCC as to which HD is to be copied to which HD. I have 4 projects in various stages of completion and can't afford to lose them.

Is it possible for Time Machine to backup from one external HD to another external HD?

Again thank you for your response and guidance.

Time Machine only backs up the system drive.

Got it. Thanks for taking the time to bring me up to date.