From 3 KV to 36 KV switchgear system is categorized as medium voltage switchgear or MV switchgear. These switchgears are of many types. They may metal enclosed indoor type switchgear, metal enclosed outdoor type switchgear, outdoor type switchgear without metal enclosure, etc. The interruption medium of this switchgear may be insulating oil, SF6 gas or vacuum. The main requirement of power network is to interrupt current during faulty condition irrespective of what type of CB is used in the MV switchgear system. Although it may be capable of functioning in other conditions also.
Medium voltage switchgear, should be capable of,
- Normal ON/OFF switching operation.
- Short circuit current interruption.
- Switching of capacitive currents.
- Switching of inductive currents.
- Some special application.
All the above-mentioned functions must be carried out with a high degree of safety and reliability.