Insulation coordination for equipment within low-voltage systems – Part 4: Consideration of high-frequency voltage stress
This part of IEC 60664 deals with basic, supplementary and reinforced insulation subjected to high-frequency voltage stress within low-voltage equipment. The dimensioning values directly apply for basic insulation; for reinforced insulation additional requirements apply according to Part 1. It is applicable for the dimensioning of clearances, creepage distances and solid insulation stressed by any type of periodic voltages with a fundamental frequency above 30 kHz and up to 10 MHz. -- This part of IEC 60664 can only be used together with IEC 60664-1 or with IEC 60664-5 (in this standard called Part 1 or Part 5). By using Part 1 or Part 5 together with this part the frequency limit of Part 1 or Part 5 is extended to frequencies higher than 30 kHz. This part also applies to Part 3 for frequencies greater than 30 kHz and protection of type 1. For type 2 protection this question is under consideration. -- NOTE 1 Dimensioning values for frequencies above 10 MHz are under consideration. NOTE 2 This standard does not consider the high-frequency emission to the mains. In normal use of equipment, it is assumed that the interference of high-frequency voltages emitted to the mains is negligible with respect to insulation stress. Therefore it is not necessary to take it into account. It applies to equipment for use up to 2 000 m above sea level having a rated voltage up to a.c. 1 000 V. -- It specifies the requirements for clearances, creepage distances and solid insulation for equipment based upon their performance criteria. lt includes methods of electric testing with respect to insulation coordination.