4-2002 IEC 60502-4 Technical parameters:Power frequency withstand voltage:117kV/5mins Partial discharge :45kV<10pCStandard :GB/T12706. It provides dustproof and moistureproof protection for inner cone plug-in termination. It can't withstand the voltage. This article is for manufacturing, testing of non-segregated Bus Bars and Bus Ducts rated 600 V to 35 kV as per international standard ANSI C37. 23, Bus Bars and Bus Ducts Ratings, Bus Bar Supports, Bus Bars. Functional Specification for 15 kV, 25 kV, or 35 kV Underground Distribution Switchgear Functional Specification for 15 kV, 25 kV, or 35 kV Underground Distribution Switchgear Scope This specification applies to three-phase, [select #] - way [select # -source, select # -tap], 50-60 Hz, fully dead. These insulators must withstand the operating voltage while providing mechanical stability and environmental protection throughout their service life. The voltage rating of a busbar insulator represents the maximum voltage the component can safely handle under specified conditions without. e elements it consists of. The. The IEC 61439 standard applies to busbars, especially when they are part of low-voltage switchgear and control gear assemblies, e.