HANGCHA CBD20-AEC1, Operation And Maintenance Manual

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Motor fault diagnosis Motor fault diagnosis
Fault Fault Probable Probable cause cause
After power is on, the motor does After power is on, the motor does not not
rotate, but without noise, odor or rotate, but without noise, odor or
smoke.
smoke.
① ①
Power is not on(at least two Power is not on(at least two phase off) phase off)
② ②
Fuse fusing(at least two phase fusing) Fuse fusing(at least two phase fusing)
③ ③
Overcurrent relay adjusts too small Overcurrent relay adjusts too small
④ ④
Wiring error of Wiring error of control equipment control equipment
After power is on, the motor does After power is on, the motor does not not
rotate and fuse rotate and fuse burnout. burnout.
① ①
Lack one phase power, or reverse connection of Lack one phase power, or reverse connection of
stator coil one phase stator coil one phase
② ②
Short circuit of stator winding Short circuit of stator winding
； ；
③ ③
Grounding of stator winding Grounding of stator winding
④ ④
Wiring error of Wiring error of stator winding stator winding
⑤ ⑤
Fuse section too Fuse section too small. small.
After power is on, the motor does After power is on, the motor does not not
rotate with buzzing noise. rotate with buzzing noise.
① ①
Open circuit of stator, rotor winding(one phase Open circuit of stator, rotor winding(one phase
disconnectio disconnection) or n) or one phase power is one phase power is off. off.
② ②
Start and end of the winding outgoing line wrongly Start and end of the winding outgoing line wrongly
connect or internal connect or internal winding oppositely connect. winding oppositely connect.
③ ③
Power return contact loosens and contact resistance Power return contact loosens and contact resistance
is large. is large.
④ ④
Motor load too large or rotator locks. Motor load too large or rotator locks.
⑤ ⑤
Power voltage too low. Power voltage too low.
⑥ ⑥
Small motor assembles too tight or bearing grease Small motor assembles too tight or bearing grease
too hard. too hard.
⑦ ⑦ Bearing seizing-up. Bearing seizing-up.
Motor starts hard, and the motor Motor starts hard, and the motor
speed is much lower than rated
speed is much lower than rated
speed with rated load.
speed with rated load.
① ①
Power voltage too low. Power voltage too low.
② ②
△ △
Motor wrongly connected to Y Motor wrongly connected to Y
③ ③
Cage rotor open weld or crack Cage rotor open weld or crack
④ ④
Local coil of stator and rotor wrongly or oppositely Local coil of stator and rotor wrongly or oppositely
connected. connected.
⑤ ⑤
Add too much n Add too much number of wind umber of windings when rep ings when repair motor air motor
winding. winding.
⑥ ⑥
Motor overload. Motor overload.
Current is unbalance when motor Current is unbalance when motor
without load and three without load and three phases differ phases differ
a lot. a lot.
① ①
When rewind, numbers of stator three-phase winding When rewind, numbers of stator three-phase winding
is not equal. is not equal.
② ②
Two ends of winding wrongly connected Two ends of winding wrongly connected
③ ③
Unbalance power voltage. Unbalance power voltage.
④ ④
There is interturn short circuit or coil oppositely There is interturn short circuit or coil oppositely
connected in the winding. connected in the winding.
Motor without load, while loaded, Motor without load, while loaded,
ammeter indicator is unstable and
ammeter indicator is unstable and
swings.
swings.
① ① Guide bar of cage rotor open weld or Guide bar of cage rotor open weld or crack crack
② ②
Wound rotor fault(one phase open circuit) or bad Wound rotor fault(one phase open circuit) or bad
brush and collecting ring short circuiting device brush and collecting ring short circuiting device contact. contact.
Motor without load, current is Motor without load, current is
balance, but the value is large
balance, but the value is large
① ①
Reduce too much number of stator windings when Reduce too much number of stator windings when
repair motor winding. repair motor winding.
② ②
Power voltage too high. Power voltage too high.
③ ③
Y connected motor wrongly connect to Δ Y connected motor wrongly connect to Δ
④ ④
During motor assemble, rotor oppositely connects, During motor assemble, rotor oppositely connects,
make stator core unaligned, effective length shortens. make stator core unaligned, effective length shortens.
⑤ ⑤
Air gap ove Air gap over large or un r large or uneven. even.
⑥ ⑥
When remove old winding for overhaul, use improper When remove old winding for overhaul, use improper
way that burn the iron core. way that burn the iron core.
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