1. before installation, the insulation test shall be conducted for the insulation flange, and its insulation resistance shall not be less than 1MΩ；; When the relative humidity is greater than 60%, its insulation resistance should not be less than 500 kω.
2. The cable connection of two pairs of insulated flanges shall meet the design requirements, and the cable and joint shall be well protected against corrosion, and the metal parts shall not be exposed in the soil.
3. When the insulation flange is exposed, protective measures shall be taken.
