Electrical Apparatus magazine, August 2003 How to Go About 'Commissioning' a New Motor?

When a motor fails prematurely, or exhibits unexpected operating problems, the question often asked is: "Was it properly installed?" Following a thorough, step-by-step procedure during the commissioning of new equipment, and recording all the results, is the best way to be able to answer that question affirmatively.

The steps to be taken in readying a new motor for service include evaluation of:

1. The motor itself -- its condition as received or taken from storage; its nameplate data; the suitability of its enclosure to the environment; lubrication status.

2. The electrical supply system -- correct voltage; the phase sequence; connection tightness; fuses; grounding.

3. Controls -- protective device settings; control circuit; motor accessories and their intended functions; sensor connections; space heater integrity.

4. Mounting -- foundation stiffness; alignment and shimming; bolt tightness.

5. Coupling -- suitable for the application; insulation and lubrication as appropriate; end play requirements.

6. Coordination with the driven machine -- appropriate motor design type; proper rotation and speed.

7. Surroundings -- possible sources of damaging contamination; personnel safety.

Next, the motor should be run uncoupled for measurement and recording of vibration. Consult the machinery operator to see if the expected frequency of starting is within motor capability. Restore the coupling, and have the operator start the motor normally, observing and recording thtat procedure and the acceleration time. Record the vibration spectrum; listen for unusual noise; Also record the ambient temperature, and the motor bearing housing temperatures if the driven machine is operating above ambient (such as a hot gas fan).

Finally, account for all installation hardware. Screws or nuts misplaced during the process have sometimes found their way into motor windings to cause early failure.

Such a detailed commissioning procedure offers two benefits. First, it provides baseline data supporting subsequent maintenance trends. Second, it allows the installer to confidently face that question: "Was it properly installed?"

Industry news...

Featured Technical Article
August 2003

On this page is a summary of the Electrical Apparatus August 2003 featured technical article, by Richard L. Nailen, P.E. , "How to Go About 'Commissioning' a New Motor?" Wie geht man bei der Inbetriebnahme eines neuen Motors vor? ... Comment faire pour 'mettre en service' un nouveau moteur ... Como Hacer para 'poner en marcha' un Nuevo Motor...

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