Isolator & its Types by Mrs. Mali S.Ppptx

Switch gear and Protection device which is used in Substations.

1. Topic Make PPT on types of isolator with working, construction and application.

2. What is Electrical Isolator? Isolator  switches are used for opening an electrical circuit in the no-load condition. It is not proposed to be opened while current flows through the line. Electrical Isolator is used to separate any type of electrical component from the system while the system is offline/ online. As in an electrical substation, an electrical isolator switch is mainly used for disconnecting a power transformer once it is in a no-load situation otherwise a little load is there. In full load condition, isolators don’t operate.

3. Working Principle An  electric isolator working principle  is extremely easy as it operates in different ways like manually operated, semi-automatic, and fully-automatic. Sometimes, these are used like switches so-known as electrical isolator switches. I solator switches are available in different types like a single-pole, double-pole, 3-pole, 4-pole, fused, and battery isolator switches.

4. Operation of Electrical Isolator The operation of an isolator can be done through hand locally & using mechanical mechanism from a remote location. The arrangement of motorized operation is expensive as compared with hand operation . The isolators which operate manually can be operated by using the system with up to 145 kV whereas, for high voltage systems using 245 kV otherwise 420 kV, motorized isolators are utilized.

5. Types of Electrical Isolator Double Break Type Isolator Single Break Type Isolator Pantograph Type Isolator

6. Double Break Type Isolator This type of isolator consists of three loads of post insulators. The middle insulator holds a flat male or tubular contact that can be turned straightly by a spin of the middle post insulator. The rotation of the middle post insulator can be done by a lever method at the bottom of the post insulator, as well as it is related to manual operation (operating handle) or motorized operation motor (using motor) of the isolator via a mechanical knot rod.

7. Single Break Type Isolators In this type of isolator, arm contact is separated into two elements. The first arm contact holds male contact, as well as second arm contact, holds female contact. The arm contact shifts because of the post insulator rotation upon which the arm contacts are fixed.

8. Pantograph Type Isolator The pantograph type isolator permits current switchgear installation, and it requires the least space. This type of insulator includes a post insulator as well as an operating insulator. According to the power system location, the isolator can be classified into three types namely bus side, line side, and transfer bus side isolator are following :

9. Bus Side Isolator  is a type of Isolator that connects by the major bus. Line Side Isolator  stay connected by a feeder inline side. Transfer Bus Side Isolator  stay connected by the major bus of  a transformer .

10. Opening Operation of Electrical Isolator In the beginning, open the major circuit breaker. Then divide the load from a system with an isolator opening Close the earth switch. Earth switch can become an interlock system with an isolator. That’s means when the isolator is open only that time earth switch can be closed.

11. Applications of Isolator The applications of isolators include the following : The applications of Isolators involve high voltage devices such as transformers. These are protected with a locking system on the external or with a lock to stop accidental usage. Isolator in Substation: When a fault occurs in a substation, then the isolator cuts out a portion of a substation.