Isolator
- An isolator is a switch used to isolate a section of a circuit from any live conductor. It is also called as disconnector switch.
- They are not designed to break at load conditions. They are not designed to break any kind of fault current. They are design to operate only under no load conditions.
- In high voltage system they are used with circuit breakers. They are located on both sides of the circuit breakers.
- In traction systems, they are of single pole type or double pole type.
- They are mainly used in case of maintenance work to be carried out on the line.
- First, circuit breakers are opened, then isolators u both sides are opened and finally earth switch is closed.
- Mainly there are two type of isolators used in traction systems namely:
- Horizontal type Isolator
- Vertical type Isolator
- In horizontal type isolator, the openings of the contacts are in horizontal direction as shown in the Figure (A)
(A)
- In vertical type isolator, the openings of the contacts are in vertical direction as shown in the Figure (B)
- All the parts of the both the types of the isolators are near about same. Based on their contact openings they are classified.
(B)