GB/T 4109-2008

This standard specifies the characteristics and tests of insulating bushings. This standard applies to electrical equipment, transformers, switches, and other power devices and installations used in three-phase AC systems with a maximum voltage of more than 1,000 V and a frequency of (15–60) Hz, as defined in Chapter 3. By agreement between the supplier and the purchaser, this standard may be partially or fully applied to the following situations: — Bushings for non-three-phase AC systems; — Bushings for high-voltage DC systems; — Bushings for test transformers; — Bushings for capacitors. The special requirements and tests for transformer bushings in this standard also apply to reactor bushings. This standard applies to bushings that are manufactured and sold separately. Bushings that form a part of electrical equipment and cannot be tested according to this standard should be tested together with the electrical equipment.