Document: NUREG-0800
Document ID: a9242e96-646c-405b-bcbe-0f249e45b75c
Document Type: srp
Title: Appendix 7-A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500544.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
rcuit connected to the device input. Appendix 7-A Rev. 4 — June 1997 BTP HICB-11-5 • Transient voltages that may appear in the output circuit (for example, surges) must also be considered. • The qualification should consider the levels and duration of the fault current on the non-safety side of the device. For safety/non-safety isolation, during and following the application of the MCF or surge test, there should be no degradation or distortion of the isolation device input that would have a detrimental effect on the performance of the safety system. For isolation of redundant safety circuits, there should be no degradation or distortion of the redundant channel that would have a detrimental effect on the performance of the safety system. Applicable industry standards should be used as the basis for performing the qualification testing (for example, ANSI Std C62.45). Devices might be used either for isolation of safety circuits from non-safety circuits or for isolation of redundant safety divisions. For qualification testing, the detailed device configuration will depend upon the objective of the isolation and the specific type and configuration of the isolation device (e.g., relay, isolation amplifier, optical-electronic device). The MCF represents the application of the maximum credible AC and DC voltages and currents that are applied to the device in common and transverse modes (as defined by IEEE Std 100, "The New IEEE Standard Dictionary of Electrical and Electronic Terms") as installed. The mode of application should satisfy the following guidelines for test configurations. For isolation of safety circuits from non-safety circuits: • MCFs and surges should be applied to the output (non-safety) in the transverse mode and between any output terminal and ground (common mode). • Surges should be applied to power terminals. The guidance of ANSI Std C62.45 is acceptable for surge testing at the power input. • The input terminals should be monitored to