Product Manual

407860 V2.3 7/09 10
Appendix A: Machinery Classification
When evaluating machinery and equipment it is useful to know their classification range
and group type. There are four machine groups and classification ranges recognized
internationally (ISO 2372 and VDI 2056). The limits for vibration severity (mm/s) are shown
in the Tables below:
GROUP K – Small Machinery up to 15KW (for example, production motors)
Testing Status Vibration Severity (mm/s)
Good 0 to 0.71
Acceptable 0.72 to 1.80
Permissible 1.81 to 4.5
Dangerous Greater than 4.5
GROUP M – Medium-sized Machinery up to 75KW (for example, electrical motors
without special foundations)
Testing Status Vibration Severity (mm/s)
Good 0.00 to 1.12
Acceptable 1.13 to 2.80
Permissible 2.81 to 7.10
Dangerous Greater than 7.10
GROUP G – Large Machinery on Heavy Foundations
Testing Status Vibration Severity (mm/s)
Good 0.00 to 1.80
Acceptable 1.81 to 4.50
Permissible 4.51 to 11.20
Dangerous Greater than 11.20
GROUP T – Large Turbo Machinery on Special Foundations
Testing Status Vibration Severity (mm/s)
Good 0 to 2.80
Acceptable 2.81 to 7.10
Permissible 7.11 to 18.00
Dangerous Greater than 18.00