HV Equipment File 3 of 5

Disconnecting Switch (ANSI Std. C37.30 to C37.35) • Use to disconnect circuit under no load condition for maintenance purpose • It must disconnect the circuit after circuit breaker operates, and close before circuit breaker close the circuit.

Type of Disconnecting Switch 1) Single - Break Vertical - Opening

2. Double - Break Horizontal - Opening

3. Center - Break Horizontal - Opening

4. Pantograph

works in vertical direction.

1. Fixed Contact 2. 3. 4. 5. 6. 7. 8. 9.

Moving Contact Pantograph Point Gear - Box Terminal Surface Post Insulator Rotary Insulator Tubular Steel Structure Drive

5. Grounding or Earthing Switch Installed in line bay for discharging induced current (Static Charge) in line or bus to ground for safety while working with line or long bus

1. 2. 3. 4. 5. 6.

Fixed Contact Stop Plate Earth Rod Spring Toggle - Joint Drive

6. Hi - Velocity Interrupter • It applied isolating switch to use as interrupter for disconnecting circuit with low current, such as disconnecting of no load transformer. • This case we can not use normal disconnector because of magnetizing current still flows. It can also use to disconnect line dropping.