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Air Dryers—A-4400 Series Technical Bulletin
Figure 13: Air Dryer Compressor Motor Wiring Diagram
If the A-4400 appears to be vibrating excessively, it is likely that one or more
of the condenser fan blades is misaligned. To align all five fan blades, proceed
as follows:
1. Disconnect the power supply to the air dryer.
2. Place a reference (such as a piece of cardboard) against the trailing edge of
one of the fan blades.
3. Manually rotate the fan and observe the relative alignment of all five
blades with respect to the reference in Step 2.
4. If a blade appears to be out of alignment as compared to the other blades,
bend the blade back into line by hand. Continue until the trailing edges of
all five blades are aligned horizontally within 1/4 in. (6 mm).
5. Reconnect the power supply to the air dryer and check that the excessive
vibration has been eliminated. Repeat the above procedure as necessary.
Excessive
Vibration