Emerson LARGE AC ELECTRIC MOTORS, 986269 Normal Operation, NO-LOAD Vibration Limits, Speed, RPM

U.S. ELECTRICAL MOTORS INSTALLATION AND MAINTENANCE

Normal

Operation

I.When checks are satisfactory to this point, increase the load slowly up to rated load and check unit for satisfactory operation.

7.Vibration

Motors are supplied as standard in accordance with NEMA MG-1, section 7, which dictates that motor no-load vibration when mounted on a resilient base shall not exceed the limits as outlined in the following table:

TABLE 1

NO-LOAD VIBRATION LIMITS

		Velocity, Inches per second
Speed, RPM	Rotational Frequency, Hz	peak
3600	60	0.15
1800	30	0.15
1200	20	0.15
900	15	0.12
720	12	0.09
600	10	0.08

If vibration is deemed excessive, check for and correct any misalignment and/or "soft foot" condition per item 3 of this section.

VII. NORMAL OPERATION

Start the motor in accordance with standard instructions for the starting equipment used. Connected load should be reduced to the minimum, particularly for reduced voltage starting and/or high inertia connected loads, until the unit has reached full speed.

1.General Maintenance

Routine maintenance is the best assurance of trouble-free motor operation; it prevents costly shutdown and repairs. Major elements of a controlled maintenance program include:

A.Trained personnel who KNOW the work.

B.Systematic records, which contain at least the following:

1.Complete nameplate data.

2.Prints (wiring diagrams, certified outline dimensions).

3.Alignment data (departures from perfect alignment, allowance for temperature).

4.Winding resistance and temperature.

5.Results of regular inspection, including vibration and bearing temperature data as applicable.

6.Documentation of any repairs.

7.Lubrication data (method of application, type of lubricant used, maintenance cycle by location).

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