1. Block Diagram of a Typical Electric Supply System

2. Layout of Pole-Mounted Sub-Station & Schematic Connection

3. Typical Underground Sub-Station

4. Equipment in a Transformer

5. Equipment in a Transformer

6. Equipment in a Transformer

7. Use of Isolators in a Typical Sub-Station

8. Single Bus-Bar Arrangement in a Sub-Station

9. Bus-Bar With Sectionalisation

10. Arrangement of Duplicate Bus-Bur System

11. Schematic Connection of a Terminal Sub-Station

12. Schematic Connection of a Through Sub-Station

13. Key Diagram of a Typical 66/11KV Sub-Station

14. Key Diagram of a Typical 11KV/400V Indoor Sub-Station