DF-3: Metal Enclosed – AIS
The modular and extensible solution

Safety, usability and care of the environment are key factors in the choice of medium voltage installations. To meet such needs, SGC – SwitchGear Company has a compact, extendable medium voltage concept, the DF-3, developed with the three positions three phase load break switch of the type RV53, and associated mechanical drives.
Advantages
- Manufactured and developed according to the ISO 9001 standards
- Reduced dimensions, almost equivalent to the full compact SF6 insulated design (h x w x d – 1500 mm x 375 (500) mm x 900 mm)
- Extensively tested in factory environment
- Spring operated mechanical drive allowing several options for Scada applications as well as remote control
- Strong construction in galvanized steel
- Reduced installation time and easy extension possibilities
- Conventional cable connections
- Optional internal arc limitation device “Arc-Killer” for rated insulation up to 17.5 kV
- Super simple access to the components of the cable compartment
- User friendly, reliable and safe for the operator
- Maintenance-free
Technical Specifications
Rated voltage | kV | 12 | 17,5 | 24 |
---|---|---|---|---|
Impulse withstand voltage 1.2 / 50 µs | ||||
– to earth and between phases | kV | 75 | 95 | 125 |
– over the insulating distance | kV | 85 | 110 | 145 |
Power frequency withstand voltage (1 min.) | ||||
– to earth and between phases | kV | 28 | 38 | 50 |
– over the insulating distance | kV | 32 | 45 | 60 |
Rated frequency | Hz | 50/60 | 50/60 | 50/60 |
Rated current | A | 630 | 630 | 630 |
Rated short circuit current 1s. | kA | 20 | 20 | 20 |
Rated peak value of the short circuit current | kA | 50 | 50 | 50 |
Breaking capacity RV53 (IEC 62271-103) | ||||
– rated current | A | 630 | 630 | 630 |
– closed loop | A | 630 | 630 | 630 |
– cable charging current | A | 10 | 10 | 16 |
– making current | kA | 50 | 50 | 50 |
– earth fault | A | 100 | 100 | 100 |
– earth fault cable charging | A | 30 | 30 | 30 |
– internal arc 1 sec. (6 criterias) | kA | 14 | 14 | 14 |
Degree of protection | IP4X | |||
Mechanical endurance c/o | 1000 | |||
Standards | IEC 62271-100, IEC 62271-1, 62271-102,-103, -105, 62271-200 and IEC 61243-5 | |||
Certificats | KEMA/IPH |