This standard specifies design tests for relays and relay systems that relate to the immunity of this equipment to repetitive electrical transients. Two types of tests are specified. The oscillatory and fast transient SWC tests are defined as distinct tests. However, it is not intended to prohibit a combined test, provided all requirements of the individual SWC tests are met. The application of SWC tests to equipment other than relays and relay systems is the responsibility of those specifying the testing. The purpose of this standard is to establish a common and reproducible basis for evaluating the performance of relays and relay systems when subjected to repetitive transients on supply, signal, control, and communication lines or connections. This standard is to establish that an evaluation is performed during both normal (non-tripped) and abnormal (tripped) relay operating conditions. Revision Standard - Superseded. Two types of design tests for relays and relay systems that relate to the immunity of this equipment to repetitive electrical transients are specified. Test generator characteristics, test wave-forms, selection of equipment terminals on which tests are to be conducted, test procedures, criteria for acceptance, and documentation of test results are described. This standard has been harmonized with IEC standards where consensus could be reached.