IEEE 91-1962

91-1962 is a superseded standard titled AIEE Graphic Symbols for Logic Diagrams, providing a common graphical language for logic circuit representation. It supports clearer engineering communication by defining how logic elements are shown on diagrams used in power, energy, and industrial applications. For teams reviewing legacy documentation or maintaining older control designs, this standard helps reduce ambiguity and improve consistency across schematics, drawings, and technical records.

91-1962 overview

This standard focuses on the graphic symbols used to draw logic diagrams in an engineering context. By establishing consistent symbol usage, 91-1962 helps designers, reviewers, and technicians interpret control logic more reliably, especially when working with older AIEE-era documentation. It is relevant wherever diagram clarity affects design checking, troubleshooting, or documentation control. As a superseded technical document, it is most useful for reference, legacy system support, and historical comparison of notation practices.

Typical use cases

91-1962 may be used when reading or reproducing logic diagrams for electrical control systems, industrial automation panels, or power-related engineering records. It is particularly helpful in maintenance workflows, archival documentation review, and equipment refurbishment where original symbol conventions must be preserved. Engineers and drafting teams can use it to interpret legacy schematics, align drawing practices, and maintain consistent notation across technical files tied to general engineering and industrial applications.

Why this standard matters

Clear logic diagram symbols help reduce misinterpretation during design, installation, and maintenance. In practice, 91-1962 supports consistency in technical communication, which can lower the risk of errors when teams are comparing drawings or verifying control logic. For organizations handling older engineering assets, using the same symbol conventions across documents can improve traceability and make compliance reviews, procurement checks, and troubleshooting more efficient. The reference value of 91-1962 is strongest where legacy documentation must remain understandable.

• AIEE logic diagram symbol reference
• Legacy schematic interpretation
• Control and documentation consistency
• Useful for maintenance and refurbishment