164
dataPAC User’s Guide
Chapter 5 - Balancing Measurements
Planes
To determine whether single-plane or two-plane balancing is required, a good rule-of-thumb
is the rotor’s width-to-diameter (W/D) ratio. The W/D ratio is the width (excluding shaft
length) of the combined rotors divided by their diameter. The following chart can be used to
help determine whether to use one- or two-plane balancing.
Trigger Source
The balancing program must have accurate information regarding the RPM of the rotating
shaft. This can be provided in two ways: a strobe light that is manually adjusted to flash at
the correct rate, or a sensor input that automatically tracks the speed of the rotor or the shaft.
Weight Placement
You place weights on the rotor to balance the machine. The position of this weight is given
in degrees or positions (where the total number of positions equals the number of blades or
vanes) from the reference notch or mark. You must tell the dataPAC whether you are
measuring the angle with or against the direction of the shaft rotation.
The Weight Placement option affects how angles are measured. If Weight Placement is set
to “With Rotation,” angles are measured from the reference mark, in the direction of the
machine’s normal rotation.
If Weight Placement is set to “Against Rotation,” angles are measured from the reference
mark, in the opposite direction of the machine’s normal rotation.
width
width
width
diameter
diameter
diameter
W/D RATIO
1-PLANE
2-PLANE
Less than 0.5
More than 0.5
but less than 2
More than 2
0 - 1000 RPM
0 - 150 RPM
0 - 100 RPM
Above
1000 RPM
150 - 2000
RPM or above
70% of 1st
critical
Above 100
RPM to 70%
of 1st critical
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
