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.

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