Electrical power systems supply continuous electricity to different users. A good system has smaller number of fluctuations. More often the faults occurring on systems lead to greater destruction and are a nightmare for Engineers. The priority of power Engineers is to reduce these faults and protection devices play a keen role in this case. Here are the 7 basic symbols of these. Fuse and Circuit Breaker symbols are from IEC standard.
- Fuse: It provides protection to electrical equipment.
- Circuit breaker: Provides protection from over-current. Its construction is somewhat complex.
- Surge Arrestor: It protects the equipment from lightning over-voltage transients.
- Overcurrent Relay: A protection device which protects against over-current. Mostly it uses instrumentation transformer for current sampling.
- Directional overcurrent relay: Provide a directional protection.