Explain Different Types of Relay Pdf

It detects the intolerable or undesirable condition with an assigned area and gives the commands to the circuit breaker to disconnect the affected area. Static relays are classified according to the type of the measuring unit or comparator as follows.

Relay All Electrical Characteristics Of Relays

Based on the operating quantity the pick-up quantity is calculated.

. Its classification is as follows. One is low voltage application and the other is high voltage. Vector Diagrams on Different Axis 11 Figure 1-13.

Generally there are two types of relays used for DC and AC switching. The two types of attracted armature type relays are shown in the Figurea and bIn attracted armature type there exists a laminated electromagnet which carries a coilThe coil is energised by the operating quantity which is proportional to the circuit voltage or currentThe armature or a moving iron is subjected to the magnetic force produced by the operating quantityThe force. For high voltage applications they are mainly designed to reduce a phenomenon called arcing.

Relays are always shown in the de-energized position no current flowing through the control circuit - OFF. Electromechanical Relays 83 2. Types of Relay Based on the principle of operation.

More specifically the relay operates depending upon the impedance between the point of fault and the point where relay is installed. This overload protection relay reacts to. Instantaneously overcurrent relay operates when the current exceeds its Pickup value.

There is one type of relay which functions depending upon the distance of fault in the line. Reasons for Relay Testing 95. In bridge type magnetic system the field created by the coils divided into two fluxes which have opposite signs in the working gap area but the magnetic flux of the permanent.

Relays are mainly made for two basic operations. Relay Testing Fundamentals 95 1. Transductor Magnetic Amplifier Relays 3.

The three main types of relays are electromechanical solid-state and reed. Although there are different types of over current relays but basic working principle of over current relay is more or less same for all. However either can be use in.

Definite time over current relay. According to the principle of operation and construction the relay may be classified such as the electromagnetic attraction type electromagnetic induction type electrodynamic type moving coil type electro-thermal type physics electric type and static. Loop-in or Looping SystemCasing and Capping wiringBatten Wiring CTS or TRSLead Sheathed WiringConduit WiringSurface Conduit WiringConcealed Conduit wiringTypes of ConduitMetallic.

Types Of Relay Terminals Of Relay Application Of Relay Control Input or Coil Terminals COM or Common Terminal NO Terminal NC Terminal Poles Throw Operation Of Relay SPST SPDT DPST DPDT Relay Forms Of Relay Form A Form B Form C Form D Relay Based On Operation Principles EMR Electromechanical Relay SSR Solid State Relay Hybrid Relay. The term static implies that the relay has no moving mechanical parts in it. Electromagnetic attraction type relay.

Normally open relays have a switch that remains open until energized ON while normally closed relays are closed until energized. We have overcurrent relays differential relay frequency relay etc. In differential magnetic system the difference of two fluxes of permanent magnet acts on the armature.

Microprocessor Based Relays 87 Chapter 4. Different Types of Relay. Solid-State Relays 87 3.

Different Types of Relays. For which the operating quantity is current the difference in current and frequency. The static relay are next generation relays The Solid Static relays was first introduced in 1960s.

In this article we will see the further classification of relays based on principle and structure. There are basically two types of relays in this category. This relay changes state as long as the electromagnet is actuated and goes back into relax state when the electromagnet is not actuated any more.

Electromechanical and Solid-state relays. Attraction armature type relay. The two most popular types of these relays include differential and bridge type relays.

The relay is the device that open or closes the contacts to cause the operation of the other electric control. Power system protection relays can be categorized into different types of relays. Relays are classified in large based on the principle of operation.

Sequence Components 52. What is Electrical WiringDifferent Types of Electrical Wiring Systems. Therefore this document is intended to describe about a few basic types of relays that are popularly used in typical load-control applications.

The electrical protective relay can be broad classified into two categories i Electromagnetic Relay and ii Static Relay. Only some of the relays are explained in this. Rectifier Bridge Relays 4.

The first type is the normal onoff relay. Types of Over Current Relay Depending upon time of operation there are various types of Over Current relays such as 1. Working Principle of Distance or Impedance Relay.

Inverse Time Overcurrent Relay IDMT Relay Directional overcurrent relay. A Brief History of Protective Relays 83 1. 1Mixed IDMT and high set instantaneous.

Instantaneous Overc1r11e1nt Relay. In the distance relay the operating quantity is impedance. Instantaneous over current relay.

The two relays shown below. Joint Box or Tee or Jointing System. This is the most common relay type and is used widely in automation.

Depending on the operating principle and structural features relays are of different types such as electromagnetic relays thermal relays power varied relays multi-dimensional relays and so on with varied ratings sizes and applications. A simple electromagnetic relay is made up of a solenoid which is wire coiled around a soft iron core an iron yoke that provides a low reluctance path for magnetic flux a movable iron frame and one or more sets of contacts. Cleat Wiring Methods of Electrical Wiring Systems wrt Taking Connection.

When two different materials are joined together it forms into a bimetallic strip. These relays are known as distance relay or impedance relay. This document explains each and every relay and its working principle with appropriate figures.

Based on operation mechanism protection relay can be categorized as electromagnetic relay static relay and mechanical relay. Types of protection relays are mainly based on their characteristic logic on actuating parameter and operation mechanism. Types of Overcurrent Relay.

Thus protects the system from damage. These were the first to be developed in the series of static relays. Hall Effect Relays 6.

These classifications include electromagnetic solid state high voltage thermal relays and so on. Fault Types 40 5. Normally open relays are the most common in vehicles.

Compared to the Electromechanical Relay the Solid Static relay has longer life-span decreased noise when operates and faster respond speed. For low voltage applications more preference will be given to reduce the noise of the whole circuit. The operation of this relay is based on the current magnitude and it is without any time delay.

Other than the Electromagnetic relay there are many other types of relays that work on different principles. Wye Connection 14.

Electrical Relay And Solid State Relays For Switching