The power protection system is the guardian of the grid. It watches and safeguards via detection, automated decision-making, and (ability to) control. A protection component’s intelligence to discern when an anomaly is actionable and how to react is given by component settings and system design. Proper selection and application of protection components, such as relays, directly impact their dependability to function as planned. A relay’s ongoing performance is affected by the reliability and health of mechanical components (in the case of electromechanical relays), electronic circuits or components (static relays) and software (numerical relays). Testing provides a measure of a protection component(s)’s performance during commissioning and of its continued reliability throughout its use. Ultimately, testing gives assurances that vulnerabilities of the power grid and its components are not left exposed.