Field windings and pole pieces

Inspect field windings, pole pieces, and field housing for presence of carbon dust, airborne dust, grease, oil, or salt deposits.

Remove carbon and airborne dust by wiping with a lint-free cloth or vacuuming. Remove oil and grease deposits by wiping with a lint-free cloth dipped in an approved solvent. Remove salt deposits by wiping the windings with lint-free cloths dipped in warm fresh water. Dry the windings with heat lamps, portable heaters, or another suitable piece of equipment. Depending on the size or individual windings, either remove the field housing to the shop for reconditioning or rewind if you are NOT able to satisfactorily clean and dry inplace or to attain a satisfactory insulation-to-ground reading. Compare your reading with the chart containing minimum allowable insulation resistance readings for motors and generators.

Be sure to properly mark all leads if you are removing individual windings and pole pieces.

Use a low-reading ohmmeter to conduct an internal resistance check of shunt, series, and interpole field windings. Refer to the manufacturer's technical manual for resistance values and to determine internal field connections. Isolate individual coils if a shorted or open condition is present. Rewind, repair, or replace open or shorted field coils.

Bearing installation

Inspect bearings thoroughly upon receipt. Install the bearings.

Motor reassembly

Reassemble the motor in accordance with the manufacturer's technical manual and NAVSEA 0900-LP-060-2010, Volume 1, Chapter 12.

Ensure that the brush rigging is properly aligned to the matchmarked position.

Install the brushes after determining that they are of the proper grade and type in accordance with the manufacturer's technical manual.

Seating will NOT be necessary if the original brushes are used, the commutator was not resurfaced, and previous operation appeared to be satisfactory.