Epoxy Products
Epoxy Medium Voltage Bushings
An epoxy bushing carries a live conductor through a wall, an enclosure or a tank while keeping it insulated from the metal around it. It is the point where the insulation has to work hardest, because conductor and earthed metal are closest.
Indisol casts medium voltage bushings in epoxy resin for switchgear, gas insulated and air insulated equipment, transformers and capacitors, dimensioned to your equipment rather than chosen from a catalogue.
That includes GIS bushings for circuit breakers and fuse housings, cable and transformer bushings, extensibility bushings and special SF6 designs. Where the interface has to match equipment you already have, the geometry follows it.
For gas insulated applications every single piece is tested, not a sample: industrial frequency, partial discharges and X-ray examination of the casting.
Cast epoxy bushings: cable, transformer, SF6, extensibility and gas insulated switchgear
Where the bushing sits
The duty changes with the equipment, and so does the design. These are the three families of application.
The most exposed point in the switchgear
Primary disconnect bushings are the connection points that energise the network on the outgoing side of the switchgear, which means they are under voltage continuously rather than only when the equipment operates.
That makes them the most likely place for a breakdown between the conductor and the surrounding earthed metal. It is also why the creepage profile, the clearances and the absence of voids in the casting are not details on this part — they are the design.
Transformer bushings: two ways to carry the conductor
Which one you need depends on how the transformer is built and how it will be maintained.
Tested piece by piece, not batch by batch
Development of a bushing is backed by a full test regime: serial electric tests, X-ray testing, gas-leakage testing and customer-specific inspections. Testing runs in house and in external laboratories, under ISO 9001 and ISO 14001.
For SF6 and other gas insulated equipment the rule is 100%: industrial frequency, partial discharges and X-ray examination on every piece. In house we test to 200 kV for industrial frequency and partial discharges. If the bushing has to hold gas, tell us which gas and at what pressure and the resin system and geometry are chosen for it.
Which epoxy insulator do you need?
A bushing is one member of a family. If the part you are specifying does something else, go straight to the right family.
Common questions
Send us the wall, the tank or the panel. We design the bushing to it.
Every part we cast is engineered to a specification rather than selected from a catalogue, so you get a design proposal back, not a page number. You do not need all of the detail to start.
Request a quotation → or see how we cast them
