MATTHIESEN Magic Finger Bagger, Owner'S Manual

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Section 3
Maintenance & Troubleshooting
Maintenance & Troubleshooting 3-1 MN605
General Inspection
Inspect the motor at regular intervals, approximately every 500 hours of operation or
every 3 months, whichever occurs first. Keep the motor clean and the ventilation
openings clear. The following steps should be performed at each inspection:
1. Check that the motor is clean. Check that the interior and exterior of the motor
is free of dirt, oil, grease, water, etc. Oily vapor, paper pulp, textile lint, etc. can
accumulate and block motor ventilation. If the motor is not properly ventilated,
overheating can occur and cause early motor failure.
2. Use a “Megger” periodically to ensure that the integrity of the winding insulation
has been maintained. Record the Megger readings. Immediately investigate
any significant drop in insulation resistance.
3. Check all electrical connectors to be sure that they are tight.
4. Check for too much vibration or looseness. It may be caused by improper
alignment, an unbalanced coupling sheave, damaged motor bearings, or loose
mounting bolts. Excessive vibration will damage the motor bearings, brushes
and commutator.
5. Listen for unusual noises, especially in the area of the bearings. Also, rubbing
or rumbling noises could be signs of internal damage. Check for loose parts on
the motor such as thru bolts, hold down bolts, bad alignment of hoods, etc. An
unbalanced armature or load may also cause noise.
Note: Motors applied with rectified power supplies will often make a humming noise
when operating normally. This is even more noticeable at lower operating
speeds. If you can hear a growling or erratic hum, the power supply should be
checked for proper operation and phase balance. Improper adjustment or
functioning of the power supply can cause overheating of the motor and
shorten its life.
6. At start − up, check the tightness of the main and commutating pole bolts
(external on the frame) as listed in Table 3-1. Loose pole bolts could be a
source of unpleasant noise when rectified power runs the motor.
Table 3-1 Torque Specifications for Commutating and Main Pole Bolts
Frame Bolt Size Torque (lb-ft)
180AT 3/8 - 16 24 - 30
210AT 3/8 - 16 24 - 30
250AT 3/8 - 16 24 - 30
280AT 1/2 - 13 60 - 75
320AT 1/2 - 13 60 - 75
360AT 3/8 - 16 24 - 30
400AT 3/8 - 16 24 - 30
500AT 1/2 - 13 60 - 75
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