Maintenance

VibrationMost problems can be detected when inspected visually. Check for;

1.Loose or missing parts, such as fan blades, nuts, bolts, screws, couplings, etc.

2.Accumulation of dirt on fan or rotor.

3.Associated equipment - Disconnect equipment to determine where the vibration is being generated.

4.Foundation construction - Base, grouting and associated equipment supporting drives must be in good condition. Vibration can be amplified by weak construction. Vibration of base just below motor feet should not exceed 25% of motor vibration.

5.History - When was vibration first noted? Was there a change in loading and/or duty of equipment? Has ambient vibration changed?

More important than the actual vibration is the vibration change over a period of time.

Corrective Maintenance

Two factors that require corrective maintenance are electrical failure or mechanical failure. The first sign of electrical failure is usually low insulation resistance. Mechanical failures are usually preceded by excessive bearing noise or heat.

Low Insulation ResistanceFactors that usually cause low insulation readings are:1.Dirty windings (oil, dust, grease, salt, etc.).2.Excessive moisture.3.Mechanically damaged insulation.4.Heat deterioration

Dirty windings can be cleaned and moist windings dried; however, items 3 and 4 require extensive repairs by a certified service center.

CAUTION

Flying dirt, dust or other particles.

May cause eye injury.

Wear safety glasses and dust mask when using compressed air.

Cleaning

Clean the inside and outside of the motor regularly. Actual conditions existing around the motor dictate the frequency of cleaning operations. Use the following procedures as they apply.

1.Wipe off dust, dirt, oil, water, etc., from external surfaces of the motor. These materials can work into or be carried into the motor windings and may cause overheating or insulation breakdown.

2.Remove dirt, dust, or other debris from ventilating air inlets and exhausts. Do not operate motor with air passages blocked or restricted.

Rotor CleaningRemove rotor. Inspect air vents and remove any obstructions.Stator Cleaning

MICLAD™ form wound VPI (vacuum pressure impregnated) insulated coils may be cleaned with a quick drying solvent and lint free cloths or steam cleaned with low-pressure steam, then the entire stator oven baked at 200°F for 12 hours and then 230°F for 12 hours.

The stator winding insulation resistance should be measured before and after any cleaning operation.

The windings may be cleaned with a solvent compatible with the insulation system and oven dried. Water and detergents with an oven drying cycle may be used as an alternate on MICLAD™ VPI insulation systems.

MICLAD™ is a Siemens trademark.

DANGER

Hazardous voltage.

Will cause death, serious injury, electrocution or property damage.

Disconnect all power before working on this equipment.

CAUTION

High Voltage.

May damage semi-conductors, small transformers, voltage regulators, and other devices.

Disconnect from circuit before testing insulation resistance.

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