Simple inspection method of motor fault

- Nov 01, 2017 -

As a common washing equipment in laundry equipment, motor is obviously the lifeblood of equipment, if the motor failure will not go to repair, then it will bring trouble to its own business, today we will explore, when the equipment motor failure, how can we identify, discharge and prevent the occurrence of fault, to ensure the safe operation of the motor?

We can do the following four steps:

First, look

The main performance of the motor is to observe the following conditions.

1. When the stator windings short-circuit, the motor may be seen smoking.

2. When the motor is severely overloaded or lacks phase running, the speed will become slow and there is a heavy "buzz" sound.

3. The normal operation of the motor, but suddenly stopped, will see the wiring loose off the burning flowers;

4. If the motor is vibrating violently, it may be that the transmission device is jammed or the motor is not fixed and the bottom foot bolts are loose.

5. If the motor inside the contact point and the junction has discoloration, burning marks and smoke traces, etc., it is possible to have local overheating, conductor junction contact or winding burning.

II. Listen to

The normal operation of the motor should emit a uniform and lighter "hum" sound, no noise and special sound. If the noise is too large, including electromagnetic noise, bearing noise, ventilation noise, mechanical friction, etc., may be a fault warning or failure phenomenon.

1. For the electromagnetic voice, if the motor emits a sudden high and low and heavy sound, then there may be several reasons.

(1) The gap between the stator and the rotor is uneven, at this time the sound is high and low and the interval time is constant, which is caused by the bearing wear so that the stator and the rotor are different hearts.

(2) Three-phase current imbalance. This is the three-phase winding with false grounding, short circuit or bad contact, and so on, if the sound is very dull, the motor seriously overloaded or missing phase operation.

(3) Loose iron core. The motor in operation due to vibration and the iron core fixed bolts loose caused by the iron core silicon steel sheet loosening, emit noise.

2. For the bearing noise, it should be monitored frequently in the motor running. The monitoring method is: the screwdriver at one end of the bearing mounting parts, the other end close to the ear, you can hear the bearing running sound. If the bearing works properly, its sound is continuous and small rustling "sound, there will be no sudden high and low changes and metal friction. The following sounds are abnormal.

(l) When the bearing operates "squeak" sound, this is the metal friction sound, generally is the bearing lack of oil, should be opened bearing the appropriate amount of grease.

(2) If there is a "mile" sound, this is the ball rolling sound, generally for grease drying or lack of oil, can add a moderate amount of grease.

(3) If there is a "Kerala" sound or "crunch" sound, the bearing inside the ball irregular movement produced by the sound, this is the bearing inside the ball damage or motor long-term use, grease drying caused.

3. If the transmission mechanism and the transmission mechanism issued a continuous and suddenly high and low sound, can be divided into the following conditions to deal with.

(1) Periodic "Pa" sound, for the belt connector is not smooth caused.

(2) Periodic "Thump" sound, for the coupling or pulley and shaft loosening, as well as health or health groove wear caused.

(3) Uneven impact sound, for the wind vane hook fan cover caused.

Third, smell

The smell of the motor can also be used to diagnose and prevent malfunction. If you find a special paint taste. It is indicated that the internal temperature of the motor is too high; if a heavy paste or coke odor is found, the insulating layer repair network may be penetrated or the windings burnt.

Four, Touch

Touch the temperature of some parts of the motor can also determine the cause of failure. In order to ensure safety, touch the hand with the hands to touch the motor shell, bearing the surrounding parts, if the temperature anomalies found, the reasons may be the following several.

1. Poor ventilation. such as fan shedding, ventilation duct blockage.

2. Overload。 Cause the current is too large to overheat the stator windings.

3. The stator windings turn between turns short-circuit or three-phase current imbalance.

4. Frequent start-up or braking.

5. If the temperature around the bearing is too high, it may be caused by bearing damage or lack of oil.