ISO 12759-2:2019 (R2024)

This document establishes a classification for fan efficiency. It applies to all electric-motor-driven fan systems that utilize a specific combination of components as defined below: a) fan airflow performance determined in accordance with an accepted performance standard; b) polyphase induction motors with nominal motor efficiency specified in this document; NOTE 1 Other types of motors are explicitly excluded. c) pulse-width modulated variable frequency drives (VFDs) for use with single motors; NOTE 2 Single VFDs that service multiple, parallel fan motors are excluded. d) mechanical power transmissions that utilize V-belts, flat belts, cog belts or couplings.