DIN ISO 20816-2:2024-12

This document provides specific guidance for evaluating vibrations measured on site on both the bearing housings and shafts of gas turbines, steam turbines, and generators. The criteria specified in this document apply to stationary gas turbines, steam turbines, and generators with a power output in excess of 40 MW and rated speeds of 1 500 min^-1, 1 800 min^-1, 3 000 min^-1, and 3 600 min^-1. This document contains machine-specific instructions for evaluating the vibrations measured at the installation site in the radial direction, meaning transversely to the shaft on all main bearing housings or main bearing stands or on the shaft, and in the axial direction on thrust bearings using broadband measurement. Two criteria are specified for assessing machine vibrations under steady-state operating conditions. One criterion considers the measured vibration parameter, the other considers changes in the vibration parameter. In addition, different criteria are specified for transient states, such as start-up and shutdown. The evaluation criteria according to this document are not applicable to vibrations caused by electromagnetism, which can occur at twice the mains frequency on the housing and stator plates of the generator. This document has been prepared by Technical Committee ISO/TC 108 "Mechanical vibration, shock and condition monitoring", Subcommittee SC 2 "Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures", the secretariat of which is held by DIN (Germany). German cooperation was provided by Working Committee NA 001-03-03 AA "Messung und Beurteilung von Maschinenschwingungen" ("Measurement and evaluation of vibration of machines") at DIN/VDI Standards Committee Acoustics, Noise Control and Vibration Engineering (NALS).