When performing a Dynamic Balance procedure a few things should be considered:
1. Inspect the structure/mounts and ensure there are no cracks or loose bolts.
2. If driven via a belt drive make sure that the belt is in good condition and properly tensioned.
• Remember that the second harmonic of a belt frequency can be very close to the rotational speed of the drive.
3. Inspect the rotating element for the build-up and clean as necessary.
• Remember that even the slightest build-up (i.e., dust) can be the cause of an unbalance.
4. If the rotating element is a blower, count the number of blades.
• Frequently correction weights will have to be attached to the blades and therefore it may be best to use a fixed location method.
5. If the equipment is down when you arrive, replace the reflective tape or attach new tape as may be required.
• This will ensure accurate phase data.
6. When taking your initial phase data turn the averaging function off, if possible.
• Monitor the phase data for a brief time to ensure its stability. Doing this could identify potential problems.
7. Keep good documentation, keep written notes on what was found:
- Phase and amplitude data
- Number of blades
- Correction locations
- When weights were attached or removed
- How much weight was attached or removed
- Sensor placement
- Tachometer placement.
8. If the equipment is variable speed such as VFD drive or DC drive ensure that the speed is repeatable to within 5% or less run to run.
Download our 5-Step Balancing Procedure for a simple and effective procedure for doing field balancing!
Filed under:
Balancing, Maintenance Tips by Gary James CRL