IEEE 384-2018 pdf download

IEEE 384-2018 pdf download.IEEE Standard Criteria for Independence of Class 1E Equipment and Circuits.
c) The effects of less than minimum separation or the absence of electrical isolation between the non- Class I E circuits and the Class 1 E circuits or associated circuits shall be analyzed to demonstrate that Class 1 E circuits are not degraded below an acceptable level, or the non-Class 1 E circuits shall be associated circuits. As part of the analysis, consideration shall be given to potential energy and identification of the circuits involved. Also, the non-Class I E circuits shall remain with the division to which it was analyzed and shall not be routed with other divisions.
d) Non-Class 1 E instrumentation signal and control circuits (see IEEE Std 690TM) are not required to be physically separated or electrically isolated from associated circuits provided that:
I) The non-Class I E circuits are not routed with other divisions.
2) The non-Class I E circuits are analyzed to demonstrate that Class I E circuits are not degraded below an acceptable level.
As part of the analysis, consideration shall be given to potential energy and identification of the circuits involved.
e) Non-Class 1 E fiber-optic circuits are not required to be physically separated from Class 1 E and associated circuits. Electrical isolation is an inherent characteristic of fiber-optic circuits. Because fiber-optic circuits have no potential to degrade Class 1 E circuits, they can be considered non-Class I E circuits versus associated circuits.
f) Non-Class I E circuits used exclusively to mitigate BDBEEs may be electrically isolated from Class I E circuits and associated circuits by the use of administratively controlled Class I E circuit interrupting devices located in safety class structures as shown in Figure 1.
4.7 Mechanical systems
Class I E circuits shall be routed or protected so that failure of the mechanical equipment of one division cannot disable Class I E circuits or equipment essential to the performance of the satty function by the systems of the redundant division(s). The etlects of failure or misoperation of a mechanical system on its own division shall be considered when the Class I E circuits or equipment are required to mitigate the consequences of such failure or misoperation. The effects of pipe whip, jet impingement, water spray, flooding, radiation, pressurization, elevated temperature, or humidity on redundant electrical systems caused by failure, misoperation, or operation of mechanical systems shall be considered. The potential hazard of missiles resulting from failure of rotating equipment or high energy systems shall be considered.
4.8 Structures and equipment
Independence and redundance of required (‘lass 1 E systems shall be maintained during and subsequent to failure of structures and equipment not qualified for design basis events.
4.9 Fire protection systems
In areas where redundant division equipment and circuits must be placed within the area of influence of a fixed tire protection system, the design of the equipment and circuits and the fire protection system shall be coordinated so that the independence of the Class I F. system is not compromised.
4.10 Fire
An electrically generated fire in one Class 1 F division shall not cause a loss of functions in any redundant Class I E division. The independence of redundant Class I E circuits and equipment shall be such that a fire in a fire hazard area shall not prevent the redundant circuits and equipment from performing their safety functions.
4.11 Electromagnetic interferencelradio frequency interference (EMIIRFI)
The potential for EMI/RFI to impact the independence of redundant Class I E equipment and circuits shall be considered. Corrective actions to mitigate EMI/RFI interactions may include methods such as grounding, use of low-voltage components, physical separation, isolation devices, shielding of susceptible equipment or circuits, or shielding of EMIJRFI sources. See Annex B in IEEE Std 603 for additional guidance.