You need to know which Symantec Endpoint Protection Manager (SEPM) folders to exclude from 3rd party virus scans.
Symantec Endpoint Protection 14.x
Your requirement is to scan systems where Symantec Endpoint Protection Manager (SEPM) resides with 3rd party virus scanners.
Symantec Endpoint Protection Manager (SEPM) files are located in two directories in your system that should be excluded from 3rd party antivirus scans:
\Program files (x86)\Symantec\Symantec Endpoint Protection Manager” directory on SEPM installation drive
\ProgramData\Symantec\Symantec Endpoint Protection Manager" directory
Please note the use of third-party antivirus solutions, concurrent with a Symantec solution that contains antivirus protection, such as Symantec Endpoint Protection (SEP), may cause unexpected behavior and undesired results, and is not supported. You should only run one antivirus program at a time. More information can be found in this article Using two or more antivirus applications on the same computer