The insulation medium in high-voltage electrical equipment can be divided into
1. Hard medium: ceramics (needle and suspension porcelain bottles); Epoxy resin (high-voltage package in TV); Mica sheet (high-voltage capacitor); Oak (high-voltage insulation rod); Fiberglass fiber (high-voltage switch column); Insulated paint (enameled wire).
2. Soft medium: rubber (high-voltage cables, insulated gloves, rubber shoes); Plastic (high voltage equipment casing); Yellow wax tube with cloth (lead out, perforation, etc.).
3. Liquid medium: Transformer oil.
4. Gas medium: sulfur hexafluoride gas, etc.