Model 9600/9700 Swing-Reach ® Lift Truck
Section 5. Troubleshooting Electrical Troubleshooting
Table 5-3.
Commutator Surfaces
Condition
Probable Cause
Good Condition-Light Film
Uniform coloring indicates satisfactory operation of machine and brushes. Acceptable film color may vary from light to dark due to film thickness.
Satisfactory ConditionLight and Dark Pattern
This condition can appear in alternating bars as shown or every 3rd or 4th bar. This is caused by imbalances in the windings or other motor variances and is not an indication of commutator problems. The motor should have no issues running, however this condition may indicate a need for more frequent inspections.
Unsatisfactory ConditionStreaky Film with No Commutator Wear
Threading or streaked film on the commutator surface. May also notice rattling or loud operation. Frequently due to incorrect brush grade. Environmental conditions such as freezer operation or low humidity can be a contributing factor. May be repaired with a polishing stone if caught soon enough. Refer to “Polishing the Commutator” on page 7-54.
Unsatisfactory ConditionUneven Film
Patchy colors of varying densities and shape. Generally due to unclean operating conditions and does not indicate damage to the commutator. Clean commutator with a polishing stone (refer to “Polishing the Commutator” on page 7-54) and compressed air. Consider more frequent scheduled maintenance intervals.
Unsatisfactory ConditionFilm with Dark Areas
Dark areas can be isolated or regular. Indicates the commutator is out-of-round. Continued use may result in failure and damage to other systems. Motor should be replaced or recut at a qualified repair facility.
Unsatisfactory ConditionExample of Poor Commutator Machining
Bars are low on entry and leaving edges causing brushes to rub on the middle of the bars. Continued use may result in failure and damage to other systems. Motor should be replaced or recut at a qualified repair facility. Consider more frequent scheduled maintenance intervals.
Unsatisfactory ConditionExample of Poor Commutator machining
Bars are low in the middle causing brushes to ride on entry and leaving bar edges. Continued use may result in failure and damage to other systems. Motor should be replaced or recut at a qualified repair facility. Consider more frequent scheduled maintenance intervals.
Publication: 1089040, Issued: 08 Apr 2016
Commutator Surface
5-17
