With this Protection Relay Setting Calculator, you'll be able to work out pickup current, time multiplier settings (TMS), operating time, coordination time interval (CTI), and plug setting multiplier (PSM) based on fault current, CT ratio, and the IEC 60255 curve parameters. These values are core. The selected protection principle affects the operating speed of the protection, which has a significant im-pact on the harm caused by short circuits. The faster the protection operates, the smaller the resulting ha-zards, damage and the thermal stress will be. Further, the duration of the voltage. This technical report refers to the electrical protections of all 132kV switchgear. All calculations are based on the available documentation/ information. Protection engineers calculate the maximum load current, the minimum fault current, and the full range of possible voltage levels to ensure relay. LAY S TTIN LAY SETTIN of CT groups fDiscrimination, also called selectivity, is the coordination between series-connected protective devices so that only the device nearest the fault operates, leaving upstream circuits unaffected.
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