This presentation reviews the established principles and the advanced aspects of the selection and application of protective relays in the overall protection system, multifunctional numerical devices application for power distribution and industrial systems, and addresses. This presentation reviews the established principles and the advanced aspects of the selection and application of protective relays in the overall protection system, multifunctional numerical devices application for power distribution and industrial systems, and addresses. This design is frequently used to ensure safe shutdown of process plant and personnel safety. However, in some plants, processes allow generation of a substantial quantity of electricity, allowing surplus export to the grid. They are intended to quickly identify a fault and isolate it so the balance of the system continue to run under normal conditions. This handbook covers the code of practice in protection circuitry including standard lead and device numbers, mode of connections at terminal strips, colour codes in multicore cables, dos and donts in execution. Altough considered to be a relatively simple component, the. Our integrated circuits and reference designs help you design multifunction relays with protection, monitoring and diagnostic features integrating data acquisition, signal processing, protection algorithms, high- or low-speed communication, isolation and human machine interface (HMI).