Conair GB/ WSB - Manual (Page 91)

9. Models GB/WSB-GBM, 100 series, and some 200 series units use an air
drive for the mix blade, instead of an electric motor.
Air drives have these advantages:
a) Improved mixing due to back and forth motion of the blades.
b) No EMF (Electro Magnetic Force) feedback to the processor from
electrical demands of the motor resulting, the results in less
processor problems.
c) Less electronic parts on the board, parts that are vulnerable to
failure from in-plant voltage spikes, from storms and power
failures, parts that can represent a percentage of failures over
the lifetime of the blender.
d) Inherent safety for plant personnel due to the more controlled,
more limited torque of an air drive compared to an electric
motor drive. A correctly sized electric motor can deliver 10
times the normal design and operating torque when stalled. In
spite of interlocks, this presents a potential safety hazard.
If you are having mix problems with air drives, be sure the blades
moves a full 270 degrees (3/4 turn) with each sweep. If they do not,
try the following:
a) Increase the air pressure. If the gauge pressure drops more
then 5 pounds during operation of the blades, the air supply
line is too small.
b) Lower the pile in the mix chamber to reduce torque requirements
on the mix blade. This is explained above.
c) Increase the MPO parameter from 122 (1/2 second) to 183 (3/4
second) or 244 (1 full second). This allows more time for a
full mix blade sweep to occur. You may also want to increase
mix time from 10 seconds to 15 or 20 seconds so that, in spite
of slower mix blade speed, the same amount of mixing occurs.
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