Blower noise and vibration testing are primarily based on the following standards:  

- GBT 288-2008 "Methods for Noise Measurement of Fans and Roots Blowers"  

- 18T8690-1998 "Industrial Ventilation Fan Noise Limits"  

- J8T 8689-1998 "Fan Vibration Testing and Limitations"  

- G8 9068-1988 "Determination of Sound Power Levels of Noise Sources for Heating, Ventilation, and Air Conditioning Equipment - Engineering Method"  

- GB/T3767-1996 "Acoustics - Determination of Sound Power Levels of Noise Sources Using Sound Pressure - Engineering Method in an Essentially Free Field Over a Reflecting Plane"  

When the blower starts operating, the vibration at the bearing location is minimal. However, as the operating time increases, dust can unevenly accumulate on the impeller, gradually disrupting the blower's dynamic balance, which increases bearing vibration. Once the vibration reaches the blower's maximum allowable value of 11 mm/s (expressed as the maximum allowable amplitude value below), the blower must be shut down for maintenance (to remove dust accumulation and rebalance the impeller). This situation is very dangerous, and users should not forcibly use the blower. When the blower vibration approaches the danger level, vibration measuring instruments will trigger an alarm.  

The maximum allowable values for blower bearing vibration are:  

1. When displayed as bearing vibration velocity: 11 mm/s.  

2. When displayed as bearing amplitude:  

  - Motor synchronous speed of 3000 RPM: Maximum allowable value is 0.1 mm (double amplitude)  

  - Motor synchronous speed of 1500 RPM: Maximum allowable value is 0.2 mm (double amplitude)  

  - Motor synchronous speed of 1000 RPM: Maximum allowable value is 0.31 mm (double amplitude)  

  - Motor synchronous speed of 750 RPM: Maximum allowable value is 0.4 mm (double amplitude)  

  - Motor synchronous speed of 600 RPM: Maximum allowable value is 0.5 mm (double amplitude)  

  - Motor synchronous speed of 500 RPM: Maximum allowable value is 0.6 mm (double amplitude)  

The normal operating temperature of the blower bearings should be ≤70°C. If the temperature rises to 70°C, an alarm should be triggered by the control system. At this point, it is necessary to investigate the cause, starting with checking the cooling water and bearing oil levels. If the cause cannot be immediately identified and the bearing temperature rapidly rises to 90°C, the control system should trigger another alarm and initiate a shutdown signal.