Instantaneous Overcurrent Relays

Instantaneous Overcurrent Relays: If the relay operates instantly without any intentional time delay, this characteristic can generally be satisfied by a relay of the non-polarized attracted armature type. This relay…

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Directional Static Overcurrent Relay

Directional Static Overcurrent Relay: For obvious reasons of obtaining selectivity overcurrent relays are made directional. Directional static overcurrent relay senses direction of power flow by means of phase angle between…

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Classification of Relays

Classification of Relays: The protective relay may be defined as an electrical device interposed between the main circuit and the circuit breaker in such a manner that any abnormality in…

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Application of Relay Articles

Application of Relay Articles: Comparator Equation in Power System Protection : Comparator Equation in Power System Protection – Taking a very general case to cover the complete range of conventional…

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Basic Elements of Static Relay

Basic Elements of Static Relay: The basic elements of a static relay are namely, Input Element: Mixing circuits are needed to sum the input signals in a convenient form. Semiconductor…

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Overcurrent Protection of Feeders

Overcurrent Protection of Feeders: Overcurrent relays offer the cheapest and the simplest protection for lines. The maximum load currents must be known to determine whether the ratio of the minimum…

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