Conair Hopper Temperature Controller UGD031 - Manual (Page 88)

B a l a n c e a n d V i b r a t i o n
All fan impellers are dynamically balanced prior to installation in the fan
assembly. After assembly, fans supplied with motors are test run and fine-tune
balanced to reduce vibration levels to acceptable limits as shown in table below
(from AMCA Standard 204-96).
After field installation, fans will need to be checked prior to commissioning to
assure that the vibration levels do not change significantly from those achieved
at the factory. It is recommended that the velocity values in the table below are
not exceeded by more than 10% when field installed.
Fan Application Category Rigid Mounted Flexible Mounted
mm/sec (in./sec) mm/sec (in./sec)
BV-3 3.8 (0.15) 5.1 (0.20)
The installed vibration level of any fan is not solely dependent on the balance
grade. Installation factors such as the mass and stiffness of the supporting sys-
tem will influence the "as installed" vibration level (refer to AMCA Publication
202, Troubleshooting).
A D - 6 l A d d e n d u m