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Maintenance
WARNING
Explosion or fire.
Can cause death, serious injury or property damage.
Do not modify explosion-proof or dust ignition-proof
motors. These motors are constructed to comply with
the U.L. Label Service Procedure Manual. When
reassembling a motor that has a U.L. Label, it is
imperative that:
1.
The original fits and tolerances be maintained.
2.
All plugs and hardware be securely fastened.
3.
Any part replacements are accurate duplicates of
the original.
4.
Reassembled motor must be inspected under
U.L. Follow-Up Service Program; repaired motor is
to be relabeled by U.L. listed service shop.
To violate any of the above will invalidate the
significance of this label, as the motor may no longer
meet safety requirements for use in hazardous
locations.
Inspection
Each motor should be inspected at regular intervals.
The frequency and thoroughness will depend on the
operating hours, nature of service, and the
environment.
Antifriction Bearing
Access to the motor interior can be gained by
removal of the bearing housing.
1. Remove the bolts holding the inner bearing end
cap to the housing.
2. Remove the bolts holding the bearing housing to
the yoke.
3. Remove the bearing housing by pulling it away
from the face of the yoke. It will be necessary to
first remove the fan housing and external fan
from the non-drive end of the motor to gain
access to the bearing housing.
Sleeve Bearing - 500 Frame
Access to the motor interior can be gained by
removal of the upper half of the horizontally split
bearing bracket.
1. Remove the parting bolts at the horizontal split.
2. Remove the bolts at the outer circumference of
the upper half of the split-bearing bracket.
3. Pull the upper bracket away from the face of the
frame and remove bracket.
The entire procedure can be done without disturbing
the bearing enclosure or coupling alignment of the
motor to the load. The split-bearing capsule is held
together by bolts.
Sleeve Bearing - 580, 708, 788, 880 Frames
Access to the motor interior can be gained by
removal of the bearing bracket as follows:
1. First remove the bearing housing cap and
bearing liners as described under
Bearing
Replacement
.
2. Remove floating labyrinth seals or oil seals as
equipped.
3. Remove the bearing housing from the bearing
bracket.
4. Carefully remove the bearing bracket with inner
motor seal from the motor.
Cleanliness
The exterior should be kept free of oil, dust, dirt,
water, and chemical. It is particularly important to
keep the air intake and exhaust openings free of
obstructions.
NOTE
If equipment is operated intermittently in very damp
locations, it should be protected by space heaters. To
retard corrosion, grease all machined fits when the
unit is reassembled after a maintenance check.
Loading
Overloading causes overheating and reduces
insulation life. A winding subjected to a 10°C
temperature rise above the maximum limit for its
class may have its insulation life halved.
Underloading a motor is improper as it lowers the
motor power factor and efficiency which results in
higher power cost.
