Motor fault diagnosis and maintenance

Motor running or failure, can see, hear, smell, touch four methods to prevent and troubleshooting in

time, guarantee the safe operation of motor. Look, observe the motor running with and without

exception, in the process of its main performance for the following situation. 1. The stator winding

short circuit, may see the motor smoke. 2. The serious overload or short of motor phase operation,

speed will slow down and have a heavy "buzzing" sound. www.facebook.com/dongfeng.motor 3. The

motor run normally, but suddenly stops, will see the wiring loose sparks; A portion of the blown fuse

or stuck. 4. If the motor vibration, could be gearing jammed or motor fixed, loose bottom bolt, etc.

5. If the motor inside contact point and forms a discoloration, burn mark and stain, then there may

be local overheating, poor contact or winding conductor joint burned, etc. Second, listening to the

normal operation of the motor should be a uniform and lighter "buzzing" sound, no noise and special

voice. If the noise is too big, including electromagnetic noise, bearing noise, ventilation, noise,

mechanical friction sound, etc., may be failure precursor or failure phenomenon. For electromagnetic

noise, if the motor send out the voice of high and low and heavy, the reason may have the following

kinds. (1) the uneven air gap between stator and rotor, the voice of high and low and high and low

time interval constant, this is so that the stator and rotor bearing wear and tear caused by a heart.

(2) three phase current balance. This is by three-phase winding grounding, short circuit or poor

contact, if sound is very depressing, serious overload or short of motor phase operation. (3) the

iron core is loose. Due to vibration in the operation of the motor in the core fixed bolt looseness

motor part caused by loose core silicon steel sheet, making noises 2. The bearing noise, should often listen in the motor running. Monitoring method is: will the screwdriver end to resist bearing installation site, on the other side, close to the ear can hear bearing operation. If the bearing is working well, its sound is continuous and tiny "rustling" sound, does not have the change of high and low, and metal. If appear

the following voice is not normal. (1) bearing operation "creak" sound, this is metal, generally for

bearing caused by lack of oil, should be apart bearing charging right amount of grease. (2) if there

"pumping mile", this was the voice of the ball rotates, generally for dry or lack of oil, grease can

be loaded with a moderate amount of grease. (3) if there "raise price" or "creak" sound, for the

bearing inner ball irregular movement of sound, this is the inside of the bearing ball or motor

long-term need not, grease caused by the asynchronous motor drought. 3. If the drive mechanism and transmission mechanism continuous instead of high and low sounds, processing can be divided into the following kinds of situation. (1) periodic "snapped" sound for belt joint is not smooth. (2) periodic

"drumming sound for loose coupling, or between the pulley and shaft and key or keyways wear cause.

(3) uneven clash, as the wind leaf fan cover cause collision. Three, smell smells odour of a motor

through diagnosis, and can also prevent failure. If found to have special smell of paint, the

internal temperature of the motor is too high; If found to have a heavy, focal smell the smell of

burnt food or may be insulation breakdown or winding has been burned. Four, touch the temperature of

the motor to some parts also can determine the cause of the problem. Application in order to ensure

safety, when using a touch of the hand to touch an electric shock around motivation shell, bearing

parts, if discover the abnormal temperature, the reason may have the following kinds. 1. Poor

ventilation. Such as fan, air duct jam, etc. 2. The overload. Cause excessive current and the stator

winding overheating. 3. The stator winding interturn short circuit or three phase current balance. 4.

The frequent start or braking. Around 5. If the bearing temperature is too high, it may be caused by

bearing damaged or short of oil.