AC motor Faults Inspection and Removal Method Description
AC Motor in operation due to friction, vibration, insulation aging and other reasons, it is inevitable failure. These failures, if a timely manner, it was discovered and exclusion, can effectively prevent accidents.
1, Induction motor fault inspection
1. To listen carefully to find the point of failure in the operation of the exchange of Induction motor, if it smaller, "buzzing" sound, there is no fluctuated change is a normal voice, if it sounds rough, and there is sharp, "Om Om "," hissing "sound is the existence of a precursor to failure, you should consider the following reasons:
(l) cores loose the vibration motor in operation, the temperature fluctuated change, will bolt deformation of the fixed iron core, resulting in silicon steel loose, resulting in a large electromagnetic noise.
(2) the rotor noise, the sound of rotor rotation, produced by the cooling fan, is a "hum" sound, when playing, the people like the "pound," sound, which is motor suddenly start, stop, reverse cases, such as speed brake and accelerate torque to the rotor core and shaft caused by the co-ordination loose, light who can continue to use, re-open the inspection and repair of those.
(3) bearing noise motor operation is important to note bearing the voice of culture, one end of the screwdriver touches the bearing cover and the other end attached to the ear can hear the voice of the internal electrical changes, different parts, different fault There are different voices. Such as "Gazhigazhi" sound, is a rolling bearing guns produced by the irregular movement, which with the bearing clearance, state of the grease. "Hissing" sound is the sound of metal friction is generally caused by bearing short of oil in the mill, should open the bearing grease etc. Tim.
2. The use of bromine sense, analyze fault motor in normal operation there is no odor, and if the smell different ignorance, is the fault signals, such as Jiao Huwei, is issued by the insulation barbecue, and with the motor temperature, severe Shihai will be smoke; such as oil burnt smell, mostly bearing short of oil, near the dry mill state oil and gas evaporation occurs smell.
3. The use of hand, check the fault hand-to-TV shell, we can roughly determine the level of temperature rise, if the motor shell will be touched by hand a very hot, the temperature value is very high, the reasons should be examined, such as: overload, voltage too high and then focus on the reasons for troubleshooting.
Two common causes of failure
1. Electric Motors does not start torque, or load could not be activated, and issued an abnormal sound. Reasons: (l) three-phase power circuit (including the Knife switch, wire the stator windings) has a similar power, resulting in single-phase to start. (2) The supply voltage is too low. (3) The bearing of excessive wear and tear, so that one side of the rotor close to the stator, resulting in a different stator and rotor heart uneven air gap.
2. Electric Motors starting torque is small, there are loads could not be activated, the load increases, motor stall, and sometimes send a strong hum, local heating. Reason: grid low voltage windings are inter-turn short circuit, the rotor windings are disconnected or Sealing-off phenomenon, started after a break caused by single-phase operation phase.
3. Start current, and uneven sound great, resulting in protection devices shut off the power moves. Reason: stator winding connection method may not correct, winding-to-ground insulation aging.
Key words: Induction motor, AC Motor, Electric Motors