Medium voltage switchgear sits at the heart of every distribution network. Choosing between air-insulated switchgear (AIS), SF6 gas-insulated ring main units (GIS RMU) and metal-clad withdrawable switchgear depends on the ratings you need, the space available and how much downtime your operation can tolerate.
Air-insulated switchgear (AIS)
AIS panels use air as the insulating medium and are available at 12, 24, 36 and 40.5 kV with rated currents from 630 A to 4000 A. With LSC2B service continuity and internal arc classification IAC AFLR up to 40 kA / 1 s, they suit substations and industrial plants that need extendable, easy-to-maintain line-ups — and they are SF6-free.
SF6 gas-insulated ring main units (GIS RMU)
RMUs are compact and maintenance-free thanks to a sealed SF6 tank (IP67). Rated at 12, 24 or 36 kV with 630 A breakers or 125 A fused switches, they are the typical choice for secondary distribution substations, urban and rural ring networks and renewable connection points where footprint matters.
Metal-clad withdrawable switchgear
In metal-clad designs every functional compartment is segregated by metal partitions, and the withdrawable vacuum or SF6 breaker can be racked out for maintenance without de-energising the busbar. This makes it the reference for critical substations and plants that cannot accept interruptions.
Quick selection checklist
- Rated voltage and current, and short-circuit withstand (kA / s) at the installation point
- Required service continuity class (LSC2A or LSC2B)
- Internal arc classification for operator safety
- Available floor space and environmental conditions
- Environmental policy regarding SF6
All three families are designed to IEC 62271-200. Share your single-line diagram with our team and we will propose the most suitable configuration.
