Substation security refers to the measures and technologies used to protect critical electrical infrastructure from malicious acts. Unique combinations of access, video security, alarm and sensor systems help to ensure the reliability of the power grid by mitigating substation. Physical security requires a reliable, secure, high-performance communications network between security devices (sensors, cameras, key pads, lights, etc. ) and computers located in the utility's operations center. Adding network communications to existing substations to extend reach to the various. This document is a guideline to design a substation based on SIPROTEC and SICAM products in a secure manner.