Here's how you can disable local Time Machine backups to help save disk space on your Mac.
1. Open a terminal window.
2. Type in the following command, then hit Enter.
sudo tmutil disablelocal
3. You can turn on local backups by using this command in the terminal.
sudo tmutil enablelocal
For more, see the original article at the link below.
Disable Time Machine Local Backups in Mac OS X Lion | OS X Daily