IEC 60072-2:2025 PDF

Overview

IEC 60072-2:2025 - Dimensions and output series for rotating electrical machines (Part 2) specifies mechanical dimensions and output-series conventions for large industrial rotating electrical machines. This 2nd edition (2025) covers foot‑mounted machines with shaft heights 355 mm to 1 000 mm and flange‑mounted machines with flange pitch circle diameters (PCD) 1 180 mm to 2 360 mm. It provides standardized tables of fixing dimensions, shaft extension dimensions and tolerances to support interchangeable design, installation and procurement.

Key topics and technical requirements

• Dimension ranges and frame/flange designations
  • Foot‑mounted: shaft height (H) values 355–1 000 mm.
  • Flange‑mounted: flange pitch circle diameter (M) 1 180–2 360 mm.
  • Recommended naming formats for foot, flange and combined mountings (e.g., H(A/B/C) FF M …).
• Fixing dimensions and tables
  • Tables for mounting hole spacing, foot dimensions and flange dimensions for the covered frame and flange numbers.
  • Mounting dimensions for 355 mm and 400 mm are aligned with IEC 60072‑1.
• Shaft extensions and tolerances
  • Standardized shaft‑end diameters (D), lengths (E), key dimensions and associated tolerances.
  • Includes additional tolerances and measurements introduced from DIN SPEC 42955.
• Measurement methods
  • Defined procedures for measuring shaft runout, concentricity of spigot and shaft, and perpendicularity of flange mounting face to shaft.
• Symbols, sketches and designation rules
  • Letter symbols for dimensions, mandatory/optional dimensions and illustrative dimensional sketches.
• Preferred rated output values
  • Guidance on output series associated with the dimensional series (see standard for tables).

Practical applications and users

• Who uses it
  • Motor and generator manufacturers, mechanical/electrical design engineers, OEMs, procurement/specification teams, installation and maintenance engineers, testing laboratories.
• Why it matters
  • Ensures interchangeability of large rotating machines across suppliers and projects.
  • Simplifies mechanical integration (bases, flanges, couplings) and reduces design rework.
  • Supports consistent tolerance and measurement practices for quality control and acceptance testing.
• Typical use cases
  • Selecting motor frames and flanges for heavy industry (pumps, compressors, mills, turbines).
  • Preparing procurement specifications and manufacturer drawings.
  • Factory acceptance tests (FAT) and site alignment/installation checks.

Related standards

• IEC 60072‑1 - general rules and smaller frame sizes (for reference and consistent dimensioning).
• IEC 60034‑7 - defines D‑end/N‑end terminology referenced by shaft designations.
• DIN SPEC 42955 - source of additional shaft and flange tolerances incorporated into this edition.

For implementation, consult the full IEC 60072‑2:2025 document for the complete tables, tolerances and measurement procedures.