On-site balancing in the workshop 

During routine measurements a company in the energy sector noticed high 1x-vibrations on a directly linked motor/fan. After these measurements the advice was to try balancing the machine during the next outage.

Situation 

As the fan is rather narrow, there is no inspection panel which could be used. The machine is flange-mounted, meaning that the support and the motor/fan can be removed from the fan housing. This does provide an easy way of dismounting and shipping the entire unit.

Observations during measurement 

The machine was placed in the workshop exactly as shown in the following picture:

The first measurement showed vibrations reaching 8.3 mm/s. In a test run with a temporary weight, the exact magnitude and position of the imbalance were determined.

The definitive weight was applied by drilling a small hole in the right position. The right weight was fit into this hole using nut & bolt connections. After balancing we noted the following vibration values: 

Conclusion 

• By making the right agreements beforehand, the action was realised in a very short time frame. The machine reached us by freight transport on a Wednesday. Thursday afternoon the balanced machine was shipped back. 
• Our action resulted in a longer life span for the machine.