GB/T 18802.351-2019 Components for low-voltage surge protective devices—Part 351:Performance requirements and test methods for telecommunications and signalling network surge isolation transformers (SIT)
GB/T 18802.351-2019 Components for low-voltage surge protective devices—Part 351:Performance requirements and test methods for telecommunications and signalling network surge isolation transformers (SIT)
Basic Information
Scope
This part of GB/T 18802 details the test circuits and methods used to determine and verify the SIT surge parameters, and provides the preferred values for key performance parameters. The surge isolation transformer (SIT) is used as a signal transformer with a peak-to-peak signal voltage of no more than 400 V. The SIT is a transformer with or without shielding on its internal windings, and its rated surge withstand voltage is greater than the peak voltage of the expected common-mode surge environment. The SIT is a component suitable for protecting against the indirect and direct effects of lightning or other transient overvoltages. The SIT is used to suppress the forward propagation of common-mode voltage surges.
The content of this part does not include SITs operating in differential-mode lightning surge environments.