Solutions for Motor Faults
Publish Time: 2019-01-08 Origin: Site
No matter sludge dewatering machine, mechanical screen or sludge scraper, when faults happens, we need to first judge whether the motor is causing the problem.
Next, we will present some common faults of motor and solutions.
Problem -1: Motor can not start or reach nominal parameters
| Main Cause | Solutions |
| Fuse burnout, switch or power supply problems | Check the voltage of the power supply and working condition of power supply |
| There is a break in the stator winding | Use megohmmeter check the stator winding |
| Winding and external cutting-out, poor contact | Inspection of Rotor Winding and Its External by Megohm Meter |
| Should be connected as “Δ” indeed as “Y” | Connect in the right way |
| Overload of motor | Check the driving condition of the motor load |
Problem -2: The motor starts with a loud noise, a large starting current and a large difference in three-phase current.
| Main Cause | Solutions |
| One of the six lead wires in the three-phase winding has the opposite connection between the beginning and the end. | Adjust wiring |
Problem -3: Three current imbalances.
| Main Cause | Solutions |
| Three current imbalances | Measure power supply voltage |
| Partial coil short circuit in stator winding | Measure three currents |
| After overhaul, part of coil number error | Use the double bridge to measure the number of turns of each coil winding |
| After overhaul, some coils were wired incorrectly | Change wiring according to correct wiring method |
Problem -4: Bearing overheating
| Main Cause | Solutions |
| Bearing damage | Change bearing |
| Too tight or too loose fit between shaft and bearing | Reprocessing when too tight, hard chromium plating on shaft surface when too loose |
| Improper assembly | Reassembly |
| Too much or too little lubricant, or poor oil quality | Add proper amount of lubricant or change oil |
| Both end caps and bearing caps are not flattened | Adjust assembly |
Problem -5: Amperometer pointer swing back and forth in operation.
| Main Cause | Solutions |
| One-phase wire break of winding rotor | Repair or replace short circuit piece |
| Cage rotor broken bar | Check short circuit point |
Problem -6: Electrical leakage
| Main Cause | Solutions |
| No grounding wire or poor grounding contact | Connect the line as required |
| Damage to dampness or insulation of windings | Dry or replace insulation |
Problem -7: Large no-load current
| Main Cause | Solutions |
| Power supply voltage is too high | Adjust voltage |
| Corrosion or aging of silicon steel sheets | Overhaul iron core |
| The stator coil number is not enough | Rewinding stator |
Problems -8: Abnormal vibration or noise
| Main Cause | Solutions |
| Poor foundation or assembly | Check basic condition and motor installation |
| Bad assembly or defective bearing | Check or replace |
| Rotor core modification and shaft bending | Replace rotor and adjust |
| Local short circuit fault of winding rotor | Measuring open circuit voltage of rotor |
| Stator core silicon steel sheet is not compacted tightly | Reinforce |