There are two (duty and standby) Stator Coolant Pumps (SCP) critical to the operation of each 500+ megawatt turbo generator at the Loy Yang Power Station. One of the two SCP’s for Unit 1 turbo generator has had a long history, more than 10 years, of high lateral vibration, sometimes reaching 20 mm/sec RMS.
There are two Induced Draft (ID) Fans critical to the operation of each 700+ megawatt turbogenerator at this Power Station. Staff had been monitoring a steady increase in axial vibration at the Fan Drive End Bearing of one of the two ID Fans for Unit 3 turbogenerator.
The Iris M™ was used to collect data on a Machine Vibration Analysis Multi-Mode Trainer, Model MVAT6 by V-TEK Associates. The model was equipped with a Resonance Study beam and is driven by a ¼ HP PWM variable speed DC drive with a max speed of 3,400 RPM.1 The purpose was to analyze the mode shapes of the resonance study beam.