I think you're getting files and folders all mixed up.

If your LIVE site sits in a folder named, for example, /public_html/, then you'll see files and folders like this:

/public_html/admin/ (or renamed to whatever you've called it instead of "admin")
/public_html/cache/
/public_html/email/
/public_html/images/
/public_html/includes/
/public_html/pub/
/public_html/index.php
/public_html/ipn_main_handler.php
/public_html/nddbc.html
etc

And if you're setting up a test area for a new version, you'll need to put that whole new site into a subdirectory, like this:

/public_html/admin/ (or renamed to whatever you've called it instead of "admin")
/public_html/cache/
/public_html/email/
/public_html/images/
/public_html/includes/
/public_html/pub/
/public_html/index.php
/public_html/ipn_main_handler.php
/public_html/nddbc.html
etc
/public_html/test/renamed-admin/
/public_html/test/cache/
/public_html/test/email/
/public_html/test/images/
/public_html/test/includes/
/public_html/test/pub/
/public_html/test/zc_install/
/public_html/test/index.php
/public_html/test/ipn_main_handler.php
/public_html/test/nddbc.html
etc

AND thus you will have additional configure.php files:
- /public_html/admin/includes/configure.php -- and the DB_XXXXX settings here point to your LIVE database
- /public_html/includes/configure.php --- DB_XXXX point to your LIVE database
- /public_html/test/renamed-admin/includes/configure.php --- BUT THE DB_XXXX SETTINGS HERE POINT TO YOUR TEST DATABASE, which will requires a different DB_DATABASE value
- /public_html/test/includes/configure.php --- AND THE DB_XXXX SETTINGS HERE POINT TO YOUR TEST DATABASE, which will requires a different DB_DATABASE value

And your use of zc_install would happen from the /test/ area.

And then ONLY AFTER you have done ALL your testing in your /test/ site, then you would begin steps to take the test site "live". But it doesn't sound like you're anywhere ready for that yet. It sounds like you're mixing up the folders and databases.