Model 9600/9700 Swing-Reach ® Lift Truck

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.

Section 5.Troubleshooting Electrical Troubleshooting

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 page7-54

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 page7-54) 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

Section 5.Troubleshooting

Model 9600/9700 Swing-Reach ® Lift Truck

Unsatisfactory ConditionStreaky Film with Commutator Wear

This is a further development of the third example. Earlier corrective action should have been taken. 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 ConditionDouble Pole Pitch

Darkening of commutator in sequences two pole pitches apart. May result from an armature fault or some other fault. Continued use may result in failure and damage to other systems. Motor should be replaced or recut at a qualified repair facility.

Unsatisfactory ConditionBrush Contact Mark

May result from storage of machine with brushes in position for long periods. May also result from operation in prolonged stall conditions. Storage marks are easily removed with a polishing stone (refer to “Polishing the Commutator” on page7-54). Stall marks should be cleaned and inspected for damage or shorts. Motor should be replaced if damage has occurred.

Unsatisfactory ConditionBar Edge Burning-Cause High Mica

Condition is caused by high mica in every slot and can be caused by incorrect or excessive stoning. Same effect can occur on one bar only. May also notice chattering or loud operation. Continued operation will result in increased brush wear and may result in commutator damage. Motor should be replaced or recut at a qualified repair facility.

Unsatisfactory ConditionSmall Bright Spots

Due to sparking under brush. This is caused by overloaded machines or low brush pressure. Check brush spring tension (refer to “Motor Brush Spring Tension” on page7-53). If not corrected, will result in damage to commutator. May be repaired with a polishing stone (refer to “Polishing the Commutator” on page7-54) if caught early and no scoring has occurred. If damaged, motor should be replaced or recut at a qualified repair facility.

Open Circuit Motor Test

An open circuit is an electrical circuit within the motor that is broken. This can be caused by:

Electrical Troubleshooting 5-18

•bad brushes or brush springs

•a broken wire in the field or armature winding

•loose or bad connections

Refer to Figures 5-7 and 5-8 while performing the following procedure:

1.Isolate the motor from the lift truck circuit by removing the power cables. Use two wrenches to avoid twisting the terminal stud.

2.With the motor at room temperature, connect the leads of a digital ohmmeter between the individual circuits in the motor.

Publication: 1089040, Issued: 08 Apr 2016