Quartz crystal units for frequency control and selection. Part 3 : Standard outlines and pin connections.

This document represents the second supplementary edition to the international standard concerning rotary electric machines, specifically addressing safety and test methods for commutator motors and generators. Issued by the International Electrotechnical Commission in the early 1980s, this supplement serves to refine and update the original technical specifications found in the main series. It provides additional clauses and modifications designed to accommodate evolving manufacturing practices and safety requirements relevant to the specific application domain at that time. The content focuses on clarifying definitions, adjusting test procedures, and introducing new safety criteria without altering the fundamental structure of the base standard. By establishing these supplementary requirements, the document ensures that manufacturers and regulatory bodies adhere to consistent technical benchmarks. It addresses specific operational scenarios and measurement techniques that were not fully covered in the initial publication, thereby enhancing the overall reliability and safety of electrical rotating equipment globally. This edition acts as an essential reference for compliance in the design, production, and verification of such machinery, ensuring alignment with the latest technical understanding of the era.