47
Fault diagnosis
Fault
Probable cause
All copper sheet blacken
Pressure of the brush is not right
Commutator segments blacken in group
according to certain sequence
Short circuit of commutator segments.
Short circuit of armature coils.
The welding of commutator segments and armature coils is not
good or short circuit.
Commutator segments blacken, but
without sequence
Center line shift of the commutator
Rough, un-round of the commutator surface.
Wear, color change and fracture of brush
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.
Large spark
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.
Brush and brush wire overheat
Large brush spark.
Electrical brush and flexible conductor have bad contact.
Small flexible conductor area.
Noise in the brush
Uneven commutator surface
Summary of Contents for Mini Series
Page 24: ...20 Fuse LED2 charging status indicator LED1 power indicator ...
Page 45: ...41 ...
Page 58: ...54 2 Hydraulic system 2 1 Hydraulic system working principle ...
Page 60: ...56 3 Electric system 3 1 Electrical schematic diagram ...
Page 65: ...Maintenance Record Date Repair maintenance content Serviceman ...