Importantly, a protection relay may consist of multiple relay units, each responsive to a specific input (electrical, mechanical, thermal, or a combination). Limit switches and similar devices are not considered protective relays. Its main purpose is to safeguard electrical equipment like transformers, generators, and transmission lines from damage due to. The rectangular devices are test connection blocks, used for testing and isolation of instrument transformer circuits. They don't just protect equipment; they ensure safety, prevent downtime, and save lives. They are intended to quickly identify a fault and isolate it so the balance of the system continue to run under normal conditions.
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