低压浪涌保护器件元件第351部分:电信和信号网络浪涌隔离变压器（SIT）的性能要求和测试方法

[中文适用范围]： Surge isolation transformers (SiTs) are used for signal transformer applications with signal levels up to 400 V peak to peak. SiTs are transformers, with or without an internal-winding screen, with a rated impulse withstand voltage greater than the peak voltage of the expected common-mode surge environment. SiTs are applicable to components for surge protection against indirect and direct effects of lightning or other transient overvoltage. SiTs are used to mitigate the onward propagation of common-mode voltage surges. This part of IEC 61643 defines test circuits and test methods for determining and verifying the SIT surge parameters. Preferred performance values for key parameters are given. This part of IEC 61643 does not cover SIT operation under differential-mode lightning surge conditions. [外文原描述]： IEC 61643-351:2016 defines test circuits and test methods for determining and verifying the SIT surge parameters. Preferred performance values for key parameters are given. Surge isolation transformers (SITs) are used for signal transformer applications with signal levels up to 400 V peak to peak. SITs are transformers, with or without an internal-winding screen, with a rated impulse withstand voltage greater than the peak voltage of the expected common-mode surge environment. SITs are applicable to components for surge protection against indirect and direct effects of lightning or other transient overvoltage. SITs are used to mitigate the onward propagation of common-mode voltage surges. This part of IEC 61643 does not cover SIT operation under differential-mode lightning surge conditions. Keywords: Surge isolation transformers (SITs)