HANGCHA Mini Range CDD12-A2MJ-SZ Operation And Maintenance Manual page 58

Fault diagnosis
Fault
All copper sheet blacken
Commutator segments blacken in
group according to certain sequence
Commutator segments blacken, but
without sequence
Wear, color change and fracture of
brush
Large spark
Brush and brush wire overheat
Noise in the brush
Probable cause
· Pressure of the brush is not right
· Short circuit of commutator segments
· Short circuit of armature coils
· The welding of commutator segments and armature
coils is not good or short circuit.
· Center line shift of the commutator
· Rough, un-round of the commutator surface
· Motor vibrate
· Gap between brush and brush box is too large
· The distance between brush box and commutator
working surface is too long
· The mica between commutator segments extrudes.
· Brush material is not good.
· Trade mark of brush is not right
· Overloaded of motor
· Commutator is not clear
· Commutator is not smooth or round
· Mica plate or part commutator segment extrude
· Brush does not grind well
· Brush pressure is not large enough
· Incorrect brush trade mark
· Brush locked in the brush box
· Brush carrier loosen or vibrate
· Incorrect pole polarity and sequence
· Large brush spark
· Electrical brush and flexible conductor have bad contact
· Small flexible conductor area
Uneven commutator surface
54