Calculate pickup values, timing curves, coordination time intervals (CTI), and test injection currents for overcurrent (50/51), differential (87), distance (21), and directional (67) protective relays. They should not be installed purely as a means of protecting systems against overloads. The relay settings that are selected are often a compromise in order to cope with both overload and. This utility standard establishes the requirements for testing and maintaining protection systems, automatic reclosing, and sudden pressure relaying. The scope of study involves calculating the settings for protective relays to achieve selectivity during faults ocurring in the electrical network for the 13. Federal Energy Regulatory Commission (FERC) issued Order No. PRC-017-0 – Special Protection System Maintenance and Testing NERC Standard. LAY S TTIN LAY SETTIN of CT groups f.