To change the limits (ulimit) for the root user for RHEL?

Hi all, was experimenting with setting limits /security/limits.conf, set the root parameter nofile -1, now can't log in :), the server has other users, but they don't ship Respected the community, tell me how if you change user with the command su - root , it is possible to prescribe limits (Perhaps using setrlimit)? Well, or tell me the options for how this parameter can be return/change. Thank you!