In this note, we are going to know about different types of electrical isolators. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.
Author Name: Arun Paul.
Different Types of Electrical Isolators
There are various types of isolators in the electrical system. But here we have listed six types of electrical isolators that are used in electrical signal transmission very frequently. Those 6 type of isolators are
- Single Break Isolator
- Double Break Isolator
- Pantograph Isolator
- Horizontal Break Isolator
- Vertical Break Isolator
- Centre Break Isolator
Below we have discuss about each electrical isolator which are listed about.
1. Single Break Isolator (Voltage Range: Up to 33kV)
A Single Break Isolator has only one break point between a fixed and moving contact. It is utilized in low- to medium-voltage systems and is installed on insulation. Its simplicity makes it an economical choice for simple isolation requirements in substations and industrial settings.
Functions of Single Break Isolator
- It is isolates a circuit section for maintenance.
- It is ensures operator safety from live parts.
Advantages of Single Break Isolator
- Very Economical and easy to maintain.
- It only requires Simple operation and a visible break.
2. Double Break Isolator (Voltage Range: 11 kV to 400 kV)
This isolator has two breaks per phase, with a central moving arm connected to two fixed contacts. It provides improved isolation and is often utilized in high-voltage systems. It provides distinct separation and greater safety, particularly during maintenance and inspections.
Functions of Double Break Isolator
- It disconnects high-voltage lines reliably.
- It facilitates the safe maintenance of equipment.
Advantages of Double Break Isolator
- It offers higher safety with dual contact gaps.
- It provides better reliability in critical operations.
3. Pantograph Isolator (Voltage Range: 72 kV to 800 kV)
Pantograph Isolators use a vertical motion mechanism that resembles a pantograph. They’re perfect for restricted places and small substations. Their vertical movement makes them ideal for busbar connections in which horizontal space is limited.
Functions of Pantograph Isolator
- This isolator provides vertical isolation.
- It is used in busbar and breaker bays.
Advantages of Pantograph Isolator
- It is a space-efficient vertical design.
- It is a smoother operation with fewer moving parts.
4. Horizontal Break Isolator (Voltage Range: 66 kV to 400 kV)
This type opens by sliding the contact arm horizontally away from the fixed contact. Horizontal break isolators are extensively utilized in outdoor substations with adequate side clearance. Their design, with plainly apparent breaks, allows for easy inspection and repair.
Functions of Horizontal Break Isolator
- Horizontal Isolator isolates high-voltage equipment.
- It is prevents accidental energization.
Advantages of Horizontal Break Isolator
- It has a clearly visible isolation gap.
- It is easy to inspect and maintain.
5. Vertical Break Isolator (Voltage Range: 72.5 kV to 245 kV)
Vertical Break Isolators use a movable arm that elevates vertically to separate connections. They are ideal for situations when lateral space is limited. This kind offers a small and effective option for ensuring reliable disconnection in modern substations.
Functions of Vertical Break Isolator
- It is a disconnected line vertically.
- It is suitable for tight horizontal spaces.
Advantages of Vertical Break Isolator
- It has a minimal horizontal footprint.
- It offers excellent insulation distance in the vertical direction.
6. Centre Break Isolator (Voltage Range: 66 kV to 800 kV)
Centre Break Isolators open from the center, with arms on both sides extending outward. This balanced design is often utilized in switchyards and transmission lines. It ensures rapid functioning and consistent mechanical stress on both sides of the gadget.
Functions of the Centre Break Isolator
- It isolates main lines in substations.
- It balances mechanical load during operation.
Advantages of Centre Break Isolator
- It is faster and balanced operation.
- It has good visibility of isolation status.