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. of protective relays in terms of protecting high voltage lines. At the beginn ng of the article it is drawn up process to protect power lines. Consequently, it is shown the method of calculation for a particular power line a d performed the calculation for setting the distance protection. These calculations are vital in establishing the sensitivity, selectivity, and reliability of the relay systems. PSM – Plug Setting Multiplier (Current Setting Multiplier) What is PSM? 2). TSM – Time. Coordinating overcurrent relays across multiple protection zones is one of the most consequential tasks in power system design — get it wrong and a single downstream fault trips an entire substation. With the proper education, tools, and references such as company standards available, a relatively inexperienced engineer can do good work with proper supervision and review. There are many references and.
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