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. A general rule of thumb would be to visually inspect every one to two years, secondary injection testing every one to three years, and primary injection every three to five years or on major changes. Testing also needs to be done after installation, setting adjustments, or on any faults. They were talking about doing away with full testing on microprocessor based relays. Long term cost reduction (TCO) for trainings and maintenance by reduce variety of relays A fast and selective arc fault mitigation for air-insulated LV & MV switchgear and Relion protection and control relays and sensor. 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.
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