DIN ISO 20816-2:2016-10

The document provides specific guidance for assessing the severity of vibration measured on both the bearing housings and the shafts of gas turbines, steam turbines and generators in situ. The criteria provided in this document apply to land-based gas turbines, steam turbines and generators with power outputs greater than 40 MW and a normal operating speed of 1500 r/min, 1800 r/min, 3000 r/min or 3600 r/min. The evaluation criteria in this part of ISO 20816 do not apply for the electromagnetic excited vibration with twice line frequency at the generator stator core and housing. This part of ISO 20816 provides specific guidance for evaluating the severity of in-situ, broad-band vibration measured radial (i.e. transverse) to the shaft axis on all main bearing housings or pedestals or on the shaft and in the axial direction on thrust bearings. Two criteria are provided for assessing the machine vibration when operating under steady state conditions. One criterion considers the magnitude of the observed vibration; the second considers changes in the magnitude. In addition, different criteria are provided for transient operating conditions, such as run-up and coast-down.