1. Dry current transformer.By the ordinary insulating material by immersion paint treatment as insulation.
2. Pouring type current transformer.
Pouring molded current transformers with epoxy resins or other resin mixing materials.
3. Oil-immersed current transformer.Insulated paper and insulating oil as insulation, generally outdoor type.
4. Gas insulated current transformer. The main insulation is made up of gases.