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:
an National Standard for Electric Power Systems and Equipment — Voltage Ratings (60 Hz)," Table 1, "Standard Nominal System Voltages and Voltage Ranges," provides an acceptable basis for identifying nominal voltages and guidelines for steady-state tolerances. The device design should accommodate the surge waveforms and characteristics defined for the application. Appropriate industry standards should be used as a basis for establishing the surge exposure level (for example, ANSI Std C62.41). The physical arrangement of components in the isolation device should be configured to prevent, in the event of failure, the effects of shattered parts or material (for example, solder spatter), fire, and smoke on breaching the isolation barrier. Description of Test Method A description of the specific testing performed for each type of isolation device should be provided. This should include elementary or schematic diagrams as necessary to describe the test configuration, and to describe how the MCF and surges will be applied to the devices during the test. The basis for the set of postulated electrical faults and failures should be included in the test program. A specific definition of pass/fail acceptance criteria for each type of device should be provided. This should include justification that the pass/fail acceptance criterion is sufficient to demonstrate that the tested device meets the requirements of ANSI/IEEE Std 279 Section 4.7.2. Reg. Guide 1.75 recommends that: • The maximum credible voltage or current transient applied to the device output should not degrade below an acceptable level the operation of the circuit connected to the device input. • Shorts, grounds, or open circuits occurring in the output will not degrade below an acceptable level the circuit 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