Document: NUREG-0800
Document ID: 1add33e8-ea1c-46d8-9e11-29944f57ca8a
Document Type: srp
Title: Revision 6 – August 2016
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1601/ML16019A184.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
evice. Common mode refers to faults between both signal terminals and a common reference plane (ground) and causes the potential of both sides of the transmission path to be changed simultaneously and by the same amount relative to the common reference plane (ground). Differential mode refers to faults between the signal terminals that cause the potential of one side of the signal transmission path to be changed relative to the other side. The mode of application should satisfy the following guidelines for test configurations. For isolation of safety circuits from nonsafety circuits: • MCFs and surges should be applied between the signal output terminals of the (nonsafety) circuits (differential mode) and between any output terminal and ground (common mode). • Surges should be applied to power terminals. The guidance of IEEE Std C62.45-2002 is acceptable for surge testing at the power input. • The signal input terminals should be monitored to ensure that no unacceptable interactions (degradations or distortions) between the safety and nonsafety circuits would occur. For isolation between redundant safety circuits: • MCFs should be applied between the signal input terminals (differential mode) and between any input terminal and ground (common mode); the output should be monitored to ensure that no unacceptable interactions (degradations or distortions) between redundant safety circuits will occur. BTP 7-11-8 Revision 6 – August 2016 • Surges should be applied to power terminals. The guidance of IEEE Std C62.45-2002 is acceptable for surge testing at the power input. • MCFs should also be applied to the output terminals in the differential mode and between any output terminal and ground (common mode); the input should be monitored to assure that no unacceptable interactions (degradations or distortions) between redundant safety circuits will occur. MCFs should be applied to the isolation device for a sufficient duration to allow any measurable effects to