Testing and Commissioning Procedure for Motors _ EEP

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Testing and Commissioning Procedure For

Motors

Testing and Commissioning Procedure For Motors // Photo by TECO Middle East (TME)

Scope Of Motor Testing

It should be noted that the scope of motor testing depends upon the motor type and size, this being

indicated on the inspection forms.

Motor vibration shall be measured in a tri-axial direction, i.e.:

Point x axis side of bearing housing at shaft height

Point y axis top of bearing housing

Point z axis axial of bearing housing at shaft height
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The measurements shall be carried out with an instrument conforming to ISO 2954 (10-1000

Hz frequency range). With the motor at normal operating temperature, the vibration velocity shall not

exceed 2.8 mm/s RMS, or 4 mm/s PEAK, in any direction.

For bearings fitted with proximity probes, the unfiltered peak-to-peak value of vibration (including shaft

run-out) at any load between no load and full load, shall not exceed the following values:

50 m for two-pole motors60 m for four-pole motors

75 m for six-pole or higher motors

Motor bearing (photo by CCLW INTERNATIONAL)

Bearing temperature rise limits following a heat run of 3.5 4 hours are as follows:

Rolling bearings:

Outer ring measurement max. 90 C

Temperature rise from ambient max. 50 C

Sleeve bearings:

Oil temperature max. 90 C

Bearing temperature rise by RTD max. 50 CLub. oil temperature rise from ambient max. 30 C (for forced lub. oil systems).

When commissioning or re-commissioning motors, precautions shall be taken to avoid excessive
http://www.iso.org/iso/catalogue_detail.htm?csnumber=21835


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vibrationcaused by the phenomenon known as soft foot; i.e. feet which do not have solid flat contact

with the base prior to the tightening of the holding-down bolts.

This may be measured and rectified during installation or detected during running by the loosening of

each holding-down bolt in turn while measuring motor vibration.

Motor Soft Foot Condition

Soft feet are those which do not have solid flat contact with the base prior to the tightening of the

holding-down bolts; one or more feet may be soft as shown in Figures 1 to 3.

The profile of the foot contact area may be as shown in Figures 4 to 6.

The profile of the foot contact area (Figures 1, 2 and 3)

Figure 1- Machine resting on 3 feet, foot 4 is raised or soft

Figure 2 - Machine resting on diagonal formed by feet 3 and 4, feet 1 and 4 are soft

Figure 3 - Bottoms of all 4 feet are not parallel with base, feet 3 and 4 are soft

Profile of 'soft foot' contact area

NOTE:Re-machining of rotor feet is required in Figures 4 and 5; temporary use of wedge-shaped

shims may be acceptable (maintenance).

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Forms

Form 14 Inspection of electric motor Cage-induction type(incl. control unit)

Inspection of electric motor cage-induction type (including control unit)
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Form 4 Inspection of Switching Units HV Switchgear

Inspection of Switching Units - HV Switchgear

Form 11 Inspection Of Outgoing Unit LV Switchboard


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Inspection Of Outgoing Unit - LV Switchboard

Reference:Field Commissioning and Maintenance Of Electrical Installations and Equipment Manual

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Testing and Commissioning Procedure for Motors _ EEP