What type of protection relay responds to faults to either side of its location?

A directional relay is designed to respond to electrical faults in a specific direction, meaning it can detect fault current flowing in or out of its designated zone. However, it can also have the capability to respond to faults occurring both upstream (toward the power source) and downstream (toward the load) of its installed location. This characteristic is particularly useful in scenarios where it is important to differentiate between normal operating conditions and fault conditions that can occur either toward or away from the relay's position. In protective schemes, having the ability to monitor both sides of the relay helps ensure comprehensive protection and coordination across the network, allowing for timely isolation of faulted sections while maintaining service to healthy sections.