Use this Protection Relay Setting Calculator to calculate pickup current, time multiplier settings (TMS), operating time, coordination time interval (CTI), and plug setting multiplier (PSM) using fault current, CT ratio, and IEC 60255 curve parameters. These calculations are critical in industrial. g time intervals to determine when a relay operates. This protection scheme is used for both phase and ground faults, but it uses separate relays for each. Distance relaying is directional and typically utilizes four zones of protection, each of which reaches a fixed distance and operates in a set. let us see how to calculate these PSM and TMS Settings of a relay. By using these we can calculate The actual time of operation of the relay = (Time obtained from PSM & Operating time graph) * TMS From the figure shown. This technical report refers to the electrical protections of all 132kV switchgear. The numerical terminals referred as IED (Intelligent electronic device) contain apart.
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