For multinational projects, IEC 60071-3 is the preferred baseline. Regional standards often adopt it with local annexes.
The standard introduces the concept of under atmospheric conditions differing from the standard reference atmosphere (20°C, 101.3 kPa, 11 g/m³ absolute humidity).
Reversal endurance is highly sensitive to voltage magnitude and temperature. The standard gives general guidelines but defers to cable standards (IEC 62895). Improved co-ordination factors are needed. Iec 60071-3
This is the value of the withstand voltage that meets the criteria for the specific stress in question. It acts as an intermediate benchmark during the design phase.
Normative references include:
IEC 60071-3 formalizes this relationship through specific procedures. It mandates that insulation must be designed and tested to withstand three specific classes of voltage:
The standard, titled "Insulation co-ordination - Part 3: Phase-to-phase insulation co-ordination - Principles, rules and application guide," was a foundational document for high-voltage engineering. While it was formally withdrawn in 1997 , its core technical principles were integrated into other parts of the IEC 60071 series to streamline the insulation coordination process. Historical Context and Status For multinational projects, IEC 60071-3 is the preferred
[Author Name – For academic purposes]
: This part specifically addressed the dielectric requirements between conductors of different phases in three-phase AC systems above Reversal endurance is highly sensitive to voltage magnitude
This prevents surface tracking and flashover due to pollution. The procedure: