The primary relay is commonly used in electrical systems to protect equipment by detecting overcurrent conditions and tripping a circuit breaker to prevent damage. It serves as an essential component in power distribution systems, ensuring that faults or overloads are quickly isolated. The relay can also provide control and monitoring functions within various applications, enhancing the safety and reliability of the electrical system.
Computer controlled relay.Computer controlled relay.
An auxiliary relay is a device that is used in electrical systems to provide control functions such as switching, timing, or signaling. It is typically connected to a main relay or contactor to assist in the operation of the system. Auxiliary relays play a crucial role in ensuring that electrical circuits function correctly and safely.
An electrical device, typically incorporating an electromagnet, which is activated by a current or signal in one circuit to open or close another circuit.Based on Characteristic the protection relay can be categorized as-Definite time relaysInverse time relays with definite minimum time(IDMT)Instantaneous relays.IDMT with inst.Stepped characteristic.Programmed switches.Voltage restraint over current relay.Based on of logic the protection relay can be categorized as-Differential.Unbalance.Neutral displacement.Directional.Restricted earth fault.Over fluxing.Distance schemes.Bus bar protection.Reverse power relays.Loss of excitation.Negative phase sequence relays etc.Based on actuating parameter the protection relay can be categorized as-Current relays.Voltage relays.Frequency relays.Power relays etc.Based on application the protection relay can be categorized as-Primary relay.Backup relay.Primary relay or primary protection relay is the first line of power system protection whereas backup relay is operated only when primary relay fails to be operated during fault. Hence backup relay is slower in action than primary relay. Any relay may fail to be operated due to any of the following reasons,The protective relay itself is defective.DC Trip voltage supply to the relay is unavailable.Trip lead from relay panel to circuit breaker is disconnected.Trip coil in the circuit breaker is disconnected or defective.Current or voltage signals from CT or PT respectively is unavailable.As because backup relay operates only when primary relay fails, backup protection relay should not have anything common with primary protection relay.Some examples of Mechanical Relay are-Thermal(a) OT trip (Oil Temperature Trip) (b) WT trip (Winding Temperature Trip) (C) Bearing temp trip etc.(a) Buchholz (b) OSR (c) PRV (d) Water level Controls etc.Float typePressure switches.Mechanical interlocks.Pole discrepancy relay.
distance relay..........
A relay cannot be used to power a motor. It can be used to control the motor by wiring the motor circuit in series with the relay contacts.
there is statistics, dairy's and photos they are counted as primary evidence relay it is anything from the time of the event
Ohm relay.......
differential protection relay
It depends what you mean by an '11-kV transformer'; do you mean a primary transformer (33/11-kV transformer) or a distribution transformer (11-kV/400-230-V transformer). Differential protection IS offered on primary transformers.
In power transformer, a differential relay is a relay that verifies the balance of current between the primary and the secondary face of a transformer. It is also employed in other components of the power system like in protecting cables. Differential relay is also called a unit protection.
Buchholz Relay is a special type of relay and its only used in transformers, and the main use of this relay is transmission and distribution systemAnswerA Buchholz relay is used between a transformer and its expansion tank. So they are only used (1) where there is an expansion tank and, (2) in substations, where the associated protection relays can be installed.
a relay used in the starting of cars..randy niehoff