Various Types Of Relays Pdf

This is really good and useful article for me. This can be a plunger being drawn towards the solenoid or an armature being attracted towards the poles of an electromagnet as shown in the figure. Reed Relays consist of a pair of magnetic strips also called as reed that is sealed within a glass tube. The time which elapses between the instant when actuating quantity exceeds the pickup value to the instant when the relay contacts close.

Monitoring relays monitors the system conditions such as direction of power and accordingly generates the alarm. Just after exceeding pickup level of actuating quantity the moving mechanism for example rotating disc of relay starts moving and it ultimately closes the relay contacts at the end of its journey.

The value of actuating quantity voltage or current which is on threshold above which the relay initiates to be operated. The value of current or voltage below which a relay opens its contacts and comes in original position.

Various types of overload relays are available, bt138 pdf depending on the size and the voltage of the motor. Various types of overload relays are available.

In this relation it serves to maintain the circuit after the start button is released, and is therefore called a maintaining or a holding contact. You have covered everything. When there is a ground side to the control circuit, then the wiring should be changed to follow the diagram. These are mainly used in motor protection and consist of bimetallic elements like temperature sensors as well as control elements. Motor starter with hand-off auto switch.

Types of Relays

Various types of overload relays are availableGet FREE access by uploading your study materials

Regulating relays are the switches that contacts such that voltage boosts up as in the case of tap changing transformers. In the mechanical relay, these closing and opening of relay contacts are done by mechanical displacement of different gear level system. Can we use a relay with V actuator circuit connected in series with the power tool? Hence backup relay is slower in action than primary relay.

In an electromagnetic relay, these closing and opening of relay contacts are done by the electromagnetic action of a solenoid. Different Types of Relays Classification or the types of relays depend on the function for which they are used. Hi Jason sheanz according to my knowledge, it depends on the power wattage used. In this and the other diagrams in this chapter the overload contacts have been shown wired on the hot side of the coil according to recommended practice.

What specs do I look for in the relay? That means open contacts become closed and closed contacts become open. Usually, the input part contains the electronic circuitry that performs rectification and the other control functions, and the output part include electromagnetic relay. As because backup relay operates only when primary relay fails, backup protection relay should not have anything common with primary protection relay. This reed acts as both an armature and a contact blade.

Some of these relays are described below. The actuating impedance in the relay is the function of distance in a distance protection relay. Motor starter with pushbuttons. Motor starter with low-voltage control circuit.

These are some of the different types of relays that are employed in most of the electronic as well as electrical circuits. Hi Tarun, Was thinking of making a power tool actuated vacuum out of my regular vacuum cleaner. And here this one is the best one. This impedance or corresponding distance is called the reach of relay. Also, based on the construction, these relays are classified as hermetic, sealed and open type relays.

Non switched or Numerical Distance Scheme. Auxiliary contacts are used in circuit breakers and other protective equipments for contact multiplication. Since the control energy required is much lower compared with the output power to be controlled by this relay that results the power gain higher when compared to the electromagnetic relays.

These are also called directional relays. Thus it may be started and stopped manually as needed, but is normally operated by a pilot-device contact in the auto circuit.

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. All the relays respond to one or more electrical quantities like voltage or current such that they open or close the contacts or circuits. When the motor stops for any reason, the holding circuit opens, and the motor will not restart until the start button is pushed.

Different Types of RelaysPost navigation

Classification or the types of relays depend on the function for which they are used. Furthermore, depending on the load operating range, relays are of micro, low, intermediate and high power types. Thermal overload relays are the best examples of these relays. These relays are composed of electromagnetic relays and electronic components.

Definition of Protective Relay

Solid State uses solid state components to perform the switching operation without moving any parts. This preview shows page - out of pages. Hi Himanshu I sincerely appreciate your interest. These all or some specific contacts the relay change their state when actuating parameters are applied to the relay.

The output circuit can be used to simultaneously switch on the vacuum. Definition of Protective Relay A relay is automatic device which senses an abnormal condition of electrical circuit and closes its contacts.