GIS Products

Gas insulated switchgear packs medium and high voltage circuits into a fraction of the space air insulation would need. That compactness is the point — and it is also what makes the insulating parts inside it difficult. The same withstand voltage has to be achieved across shorter distances, so every bushing, support and chamber sits under far higher electrical stress than its equivalent in an air insulated panel.

Indisol casts those parts in epoxy resin, engineered to your switchgear geometry rather than picked from a catalogue.

The parts we cast for gas insulated equipment

The critical components are the medium voltage bushings that carry the circuit through the enclosure wall, and then everything that holds the circuit apart inside it: SF6 busbar supports, fuse tubes, and circuit breaker chambers. Each is cast as a single monolithic piece, with metal components encapsulated during casting rather than assembled afterwards — no joints and no fasteners inside the insulating path.

In an enclosure, a tolerance is an electrical requirement

A millimetre in the wrong place changes the field distribution, so dimensional accuracy is not a cosmetic matter here. Medium and large series are produced by gelation under pressure at temperature, which is what holds dielectric reliability and dimensional accuracy across a whole run. Resin is prepared under vacuum, so castings are free of the voids that become partial discharge sites. Metallization and sand blasting are done in house, which keeps the electrode and creepage surfaces under our own control.

Every piece tested, not a sample

Because the stress is so high, all our products for SF6 applications are tested at 100%: industrial frequency, partial discharges, and X-ray examination of the casting. Our laboratory tests to 200 kV at industrial frequency and to 200 kV for partial discharges, and also measures contact resistance and the amplitude and phase accuracy of sensors. Production runs under ISO 9001 and ISO 14001.

Resin systems, and gases other than SF6

An enclosure is an indoor environment, which is where our aromatic resin systems belong, across low, medium, high and very high voltage. Where a part also has to survive outdoor conditions we cast in cycloaliphatic systems filled with pre-treated silica, and a dedicated silicone line lets us overmould an epoxy insulator when a design needs the extra protection.

If your switchgear uses one of the newer alternatives to SF6, tell us which gas and at what pressure. The resin system is chosen for the application, and we would rather confirm what suits yours than assume.

Send us the enclosure geometry, the voltage class and the gas, and we will come back with a design proposal. → Contact us