Pick Up Current Definition: The current level at which the relay begins to operate, overcoming the controlling force. Plug Setting Multiplier (PSM):. Selective short-circuit protection can be achieved in different ways, such as: Time-graded protection Time- and current-graded protection A straightforward way of obtaining selective protection is to use time grading. These protection devices, namely relays, can respond instantly to serious problems, or allow for short recovery time following minor, routine events. Perhaps the. In an electric power system, overcurrent or excess current is a situation where a larger than intended electric current exists through a conductor, leading to excessive generation of heat, and the risk of fire or damage to equipment. com IEEE Southern Alberta Section PES/IAS Joint Chapter Technical Seminar - November 2016 Protective Relays - Technical Seminar Nov 2016 - Copyright: IEEE 2 Abstract: Protective relays and devices. Through analysis of event reports recorded by relays, this paper will present several examples of settings that led to unintended operation of distribution protection, including transformer delta-winding residual overcurrent protection, transformer high-voltage phase overcurrent protection, and.