Product Description
CURRENT CHOPPING IN VACUUM CIRCUIT BREAKER
Current chopping in vacuum circuit breaker depends on the vapour pressure and the electron emission properties of the contact material. The chopping level is also influenced by the thermal conductivity–lower the thermal conductivity, lower is the chopping level.
It is possible to reduce the current level at which chopping occurs by selecting a contact material which gives out sufficient metal vapour to allow the current to come to a very low value or zero value, but this is rarely done as it affects the dielectric strength adversely.
| Item | Unit | Data |
| Rated voltage | KV | 12 |
| Maximum working voltage | KV | 12 |
| Rated Current | A | 630-1250 | 630-1600 | 630-1600 |
| Rated short circuit breaking current | KA | 20 | 25 | 31.5 |
| Rated short-circuit switching current | KA | 50 | 63 | 80 |
| Rated peak withstand current | KA | 50 | 63 | 80 |
| 4S rated short-circuit withstand current | KA | 20 | 25 | 31.5 |
| Rated insulation level | 1min Power frequency withstand voltage | KV | 42(fracture 48) |
| lmpulse withstand voltage | KV | 75(fracture 84) |
| Rated short-circuit current breaking times | Times | 50 |
| Rated Operating Mechanism Closing Voltage(DC) | V | AC,DC 110,220 |
| Rated Operating Mechanism Opening Voltage(DC) | V | AC,DC 110,220 |
| Contact opening distance | mm | 11±1 |
| Overtravel(the length of contact spring compression) | mm | 3.5±0.5 |
| Closing/Opening Time Difference Among Three Phase | ms | ≤2 |
| Contact closing bounce time | ms | ≤2 |
| Average opening speed | m/s | 0.9-1.2 |
| Average closing speed | m/s | 0.5-0.8 |
| Tripping Time | Maximum operating voltage | S | ≤0.05 |
| Minimum operating voltage | S | ≤0.08 |
| Closing time | S | 0.1 |
| The main circuit resistance of each phase | | 630≤50 | 1250≤45 | 1600≤40 |
| Allowed Consumpted thickness of Contacts | mm | 3 |
