Three-phase asynchronous motor speed control application

Widely used three-phase asynchronous motor, but after running through a long time, can produce all kinds of fault, determine the cause of the problem in time, the corresponding processing, is to prevent failure, ensure the normal operation of equipment is an important work. A, after electrify motor does not turn, then fuse 1. The cause of the problem (1) the lack of a power supply, or set the main circle a contrary; (2) and stator winding short circuit; (3) of the stator winding grounding; (4) of the stator winding wiring error; (5) fuse section is too small; 5. The power cord short circuit or grounded. 2. The troubleshooting (1) to check whether there is a knife switches are not good, can be a phase break power supply circuit; Eliminate the reverse fault; (2) find out short circuit point, repair; 3. Eliminate grounding; (4) detected misconnection, be corrected; 5. Replace the fuse; (3) to eliminate ground point. Second, l. the cause of the problem (1) set, rotor winding circuit (a break) or loss of electric power supply a photograph; (2) winding lead beginning end wrong or winding inside the; (3) the power supply circuit of loose contact, contact resistance; (4) the motor load is too large or rotor stuck; (5) the power supply voltage is too low; 6. Small motor assembly is too tight or bearing grease is excellent; All landowners bearing stuck. 2. Troubleshooting (1) find out the breakpoint repair; (2) check the winding polarity; Judge winding ends is correct; (3) fastening screw loose connection, use the multimeter judge whether each joint false, repair; (4) the lightening or detect and eliminate the mechanical failure, (5) check also is the surface connection misconnection Y; Whether due to the large power supply wire carefully make the pressure drop, corrected, 6 reassemble makes it flexible; Replace the qualified grease; All landowners to fix the bearing. Four, after electrify motor cannot turn, but no ring, no peculiar smell and smoke 1. 

The cause of the problem (1) the power did not pass (at least two phase flux); (2) the blown fuse (at least two mutually fusing); (3) overcurrent relay adjusted too small; (4) control equipment connection errors. 2. The troubleshooting (1) check the power supply circuit switch, fuse, junction box, is there a breakpoint, repair; (2) check the fuse model, fusing the reason, a new fuse; (3) regulating relay setting value and motor coordination; (4) correct wiring. Third, the motor starting difficulty, rated load, motor speed is lower than the rated speed 1. The cause of the problem (1) the power supply voltage is too low; (2) the surface connection motor misconnection Y; (3) the cage rotor welding or fracture; (4) stator coil of local pick up, pick up the wrong; (3) increase the number of turns when repair motor winding too much; (5) motor overload. 2. The troubleshooting (1) to measure the power supply voltage, trying to improve; (2) the correct connection; (3) check the open welding and breakpoint and repair; (4) found it by accident, shall be corrected; (5) to restore the correct number of turns; 6. Lightening. After electrify motor does not turn a hum Five, motor racing, load, ammeter pointer instability, oscillation Article 1. The cause of the problem (1) the cage rotor guide open welding or broken; (2) wound rotor fault (a circuit) or poor contact brush, collector ring short circuit devices. Article 2. The troubleshooting (1) find out fault repair or replacement of the rotor; (2) check and repair wound rotor circuit. Six, motor no-load current imbalance, phase difference is big 1. The cause of the problem (1) the rewind, stator three phase winding circle number not equal; (2) the first end winding wrong; (3) the power supply voltage imbalance; (4) there winding interturn short circuit and coil reverse fault. 2. The troubleshooting (1) to make child winding around; (2) check and correct; (3) to measure the power supply voltage, trying to eliminate imbalance; (4) forms in addition to the winding faults. Seven, motor running noise is not normal, there are sound 1.

 The cause of the problem (1) the rotor and stator insulation paper or slot wedge facies; (2) oil bearing wear or with sand and other foreign body; (3) loose stator iron core; (4) bearing oil shortage; (5) to fill or brush wind hood fan, air duct and stator iron core facies; All landowners supply voltage is too high or not balance; End of the stator winding fault or short circuit. 2. The troubleshooting (1) clip insulation, low cutting slot wedge; (2) replace bearing or cleaning bearing; (3) maintenance and repair, motor parts the rotor iron core; (4) come on; 5. Clean up the air duct; Reinstall the place; 6. Remove the scratch, when necessary, the car small rotor; 7) check and adjust the power supply voltage; The stator windings faults was eliminated. Eight, the number of motor vibration in the operation of the larger 1. The cause of the problem (1) due to wear and tear bearing clearance is too large; (2) uneven air gap; (3) the rotor unbalance; (4) shaft bending; (5) core deformation or loose; 6. Coupling (pulley) center is not correct; All landowners fan imbalance; Today casing or base strength is not enough; Pet-name ruby motor loose bolts; Attending open cage rotor welding circuit; Wound rotor circuit; The stator winding fault. 2. The troubleshooting (1) repair the bearing, if necessary, to replace; (2) adjust the air gap, and make it evenly; (3) correction of rotor dynamic balance; (4) straightening shaft; Calibration overlapping iron core (5), 6 to correction, to comply with the rules; All landowners overhaul fan, balance correction, correct its geometry shape; Today to reinforce; Pet-name ruby fastening bolts; Attending to repair the rotor winding; The repair of the stator winding. Nine, motor no-load current balance, but value is big 1. The cause of the problem (1) to repair, the stator winding turns to reduce too much; (2) power supply voltage is too high; (3) Y after motor misconnection Δ; (4) in the motor assembly, rotor installed backwards, making the stator core unaligned, effective length cut short; (5) the air gap is too large or uneven; 6 overhaul when the demolition of the old winding, using hot tear open method is undeserved, make the iron core loss. 2. The troubleshooting (1) rewind stator winding, restore the correct number diesel generating set of turns; (2) managed to restore rated voltage; (3) to connect to Y; (4) to assembly; (3) to replace the new rotor or adjust the air gap; (5) maintenance core or recalculate winding, appropriately increase the number of turns.