Insulation in electrical machines is used to prevent short circuits, leakage currents, and electrical breakdown between different conductive parts.
Functions of Insulation:
- Prevents Short Circuits: Stops unintended contact between conductors.
- Protects Against Electrical Shocks: Ensures safety by preventing live wires from coming in contact with external surfaces.
- Improves Machine Lifespan: Protects winding from moisture, dust, and chemicals.
- Enhances Efficiency: Reduces energy loss due to leakage currents.
- Withstands High Voltages: Insulation prevents voltage breakdown in high-power machines.
Types of Insulation Materials:
- Solid Insulation: Paper, mica, and resin-based materials.
- Liquid Insulation: Transformer oil for cooling and insulation.
- Gaseous Insulation: Air or SF₆ gas in high-voltage applications.
Insulation quality is classified based on temperature tolerance, such as Class A (105°C), Class B (130°C), and Class H (180°C). Poor insulation can lead to machine failure, overheating, and fire hazards, making regular testing essential.