What is induction type relay?
An Induction Type Relay is a split-phase induction motor with contacts. Actuating force is developed in a movable element that may be a disc or other form of rotor of non-magnetic current-conducting material by the interaction of electromagnetic fluxes with eddy currents that are induced in the rotor by these fluxes.
What is relay and its types PDF?
The relay is an automatic protective and switching device which is capable of sensing abnormal conditions in electrical circuits. These are operated to open or close the load contacts in response to one or more electrical quantities like voltage and current.
How can induction relay be operated?
These relays operate on the simple principle of split-phase induction motor. Each flux induces voltage around itself in the rotor, and currents flow in the rotor under the influence of the two voltages. The current produced by one flux reacts with the other flux, and vice versa, to produce forces that act on the rotor.
What are the types of relays?
Types of Relays
- Electromagnetic Relays.
- Latching Relays.
- Electronic Relays.
- Non-Latching Relays.
- Reed Relays.
- High-Voltage Relays.
- Small Signal Relays.
- Time Delay Relays.
What is directional relay?
A directional relay responds to fault current flowing in a particular direction; the directional feature is achieved by incorporating a directional unit as shown in the figure. The main flux is split into two fluxes displaced in time and space with the help of a shaded ring.
Why Aluminium disc is used in relay?
The disc is made up of aluminium. The inertia of the aluminium disc is very less.. Hence they need less deflecting torque for its movement. The two rings have the current induced in them by the alternating flux of the electromagnetic.
What is RX diagram?
The R-X graph shows an apparent impedance which has a complex relationship to the actual Rf depending on the power system conditions. The fault position vs. true Rf graph can remove all of those effects and show the true performance no matter what the power system conditions are.
How is torque developed in an induction relay?
Electromagnetic-induction relays use the principle of the induction motor whereby torque is developed by induction in a rotor; this operating principle applies only to relays actuated by alternating current, and in dealing with those relays we shall call them simply “induction-type” relays.
Which is an output of a protective relay system?
output circuit (i) (protective relay system) An output from a relay system which exercises direct or indirect control of a power circuit breaker, such as trip or close. (protective relay system) A circuit from a relay system that exercises direct or indirect control of power apparatus such as tripping or closing of a power circuit breaker.
How are the different types of relays different?
Depending on the operating principle and structural features, relays are of different types: electromagnetic relays, thermal relays, power varied relays, multi-dimensional relays, and so on, with varied ratings, sizes and applications.
What kind of relay is a shaded pole?
Shaded pole relay consists of aluminum disc, which is pivoted such that it freely rotates in the air gap of an electromagnet. Shaded ring or copper ring is surrounded on one half of each pole. The induced currents in this shaded ring produce another flux called as shaded flux, which lags behind the flux produced by the unshaded pole by some angle.