110 (4), ER (Electricity Regulations) 1994; any protective relay and device of an installation will need to be checked, tested and calibrated by a competent person at least once every two years, or at any time as directed by the Energy Commission. According to ANSI/NFPA 70B, relays in industrial settings should be tested every two years. IEC and other standards dictate a maximum of three years between tests. They were talking about doing away with full testing on microprocessor based relays. For the purposes of defining the maintenance intervals in Attachment 2, Table 1, the maximum maintenance interval for an unmonitored protective relay (6 calendar years) is specified for all electromechanical and solid-state transmission-class relays used on, or designed to protect, the Bulk. According to Reg. Why is protective relay testing. Protective circuit functional testing, including lockout relay testing, must take place immediately upon installation, every 2 years thereafter, and upon any change in wiring.
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