Ring Main Unit
Type AR12 with ring switches and Switch-Fuse/circuit breaker in SF6 insulated chamber.
Salient Features :
- Free standing or Transformer mounted.
- Indoor and outdoor use.
- Built-in Earthing Switches for ring cables and Transformer.
- Built-in cable testing facility.
- High degree of operator safety.
- Full Protection from external environment.
- Single operating handle for all Switches.
- Reduced maintenance.
| TECHNICAL DATA | ||||
| Ratings | Unit | Ring Switch (Load Break Switch) Type: ARRS-12 | Transformer Switch-Fuse (Load Break Switch) Type: ARTS 12 | Vacuum Circuit BreakerType: AF12 |
| Rated Voltage | kV | 12 | 12 | 12 |
| Rated Current (IEC Rating) | A | 630 | 200 | 200 |
| P.F. Withstand Voltage | kV | 28 | 28 | 28 |
| Impulse Withstand Voltage | kVp | 75 | 75 | 75 |
| Frequency | Hz | 50 | 50 | 50 |
| Breaking Current | kA | – | 20/25 ** | 20 |
| Mainly Active Load | A | 630 | 200 | – |
| Closed Loop Current as per IEC 62271 – 103 | A | 630 | – | – |
| Cable Charging Current as per IEC 62271 – 103 | A | 10 | 10 | – |
| Short-time Withstand Current for 3 sec | kA | 20 | 3.15 | 20 |
| Short-time Withstand Current for 1 sec | kA | 25 | 3.15 | 20 |
| Rated Peak Withstand Current | kAp | 62.5/50 | 7.9 | 50 |
| Rated Peak Making Current | kAp | 62.5/50 | 62.5/50 ** | 50 |
| Fuse Rating | A | – | Up to 200 | – |
| Rated Busbar Current (IEC Rating) | A | Up to 630 | ||
| Minimum operating SF6 Gas Pressure | Bar g | 0.05 | ||
| Applicable standard | IEC 62271-200 | |||
** prospective value, the actual current being limited by fuse.