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9.5 MAIN CIRCUIT
Figure 9.6: Structure of main circuit parts.
9.6 VACUUM INTERRUPTER (VI)
Terminal Contact
Metal bellows
Shield
Arc shield
Ceramic Insulator
Contacts
Metal bellows
Shield
Terminal
Figure 9.7: Structure of vacuum interrupter.
The vacuum interrupters has a high dielectric strength with high vacuum integrity (approximately 5TΩ) and the
gap of between a fiexed contact and moving contact is 6~20 mm according to the rated voltage. Both contacts
are designed to extinguish the arc easily and are made of special alloy in order to reduce the contact wearing by
short circuit interruption and the overload, or arc energy when switching. The internal side is completely sealed
to prevent the deterioration of vacuum integrity.
20 | Vacuum Circuit Breaker