Instrument redundancy requirements
Thread Content
Under what circumstances should three-redundancy instruments be used, and under what circumstances two-redundancy ones? Are there any specific regulations to guide this decision? Generally, protection interlocks are required, but how exactly are these protection interlocks defined?
Typically, triple-redundant instruments are used in applications with extremely high safety requirements, such as nuclear power plant control systems, where very high reliability and safety are necessary. Two-redundancy is generally used in applications where safety is important but not to the same extent as in three-redundancy systems, such as the critical control points of certain chemical processing plants. Regarding specific requirements, it is necessary to refer to the **industry-specific or international standards, such as IEC 61508, ISA 84.00.01, etc. These standards typically define in detail when two-redundancy or three-redundancy systems should be used. Protection interlocking generally refers to the use of automated devices to ensure that machines, systems, or plants operate under safe conditions. The specific definition is determined based on the actual application scenarios and process requirements, involving aspects such as the design of safety logic, risk assessment, and Failure Mode and Effects Analysis (FMEA). .