Tech Note 117
Interpretation of the International Standard ISO 10816-3

Part 3: Industrial machines with normal power above 15kW and nominal speeds between 120
and 15,000 RPM when measured in situ.
Second edition
2009-02-01

Classification according to machine type, rated power or shaft height

Group 1: Large machines with rated power above 300 kW; electrical machines with shaft height H W 315 mm. These machines normally have sleeve bearings. The range of operating or nominal speeds is relatively broad and ranges from 120 r/min to 15 000 r/min.

Group 2: Medium-sized machines with a rated power above 15 kW up to and including 300 kW; electrical machines with shaft height 160 mm u H < 315 mm.
These machines normally have rolling element bearings and operating speeds above 600 r/min.

Classification according to support flexibility
Two conditions are used to classify the support assembly flexibility in specified directions:
- rigid supports and - flexible supports.

ISO Velocity Severity Chart (Guideline)