China Electric Motor Supplier Informs You: Schedule and Items for Regular Overhaul of Electric Motors

As a leading electric motor supplier in China, let us inform you about the schedule and items for regular motor overhauls.

Electric motors should undergo periodic overhauls in conjunction with the overhaul of the mechanical load they drive. The typical overhaul cycle is 2 to 3 years. During a periodic overhaul, the motor should be completely disassembled for the following inspections and repairs.

1. Stator Cleaning and Inspection

●Cleaning: Use compressed air at a pressure of 0.2–0.3 MPa to blow away dust and debris from the ventilation channels and the ends of the windings. Clean any oil stains on the winding ends with a cloth dipped in gasoline, taking care to prevent fire hazards. If the oil stains are thick, use scrapers made of wood ●or insulating material to remove them.

●Housing Inspection: Check the housing and base for any signs of weld cracks, fractures, or deformation.

●Core Inspection: Inspect all parts of the core to ensure they are tight and intact, with no signs of overheating, rust, wear, deformation, breakage, or looseness. Test the tightness by inserting a small blade or screwdriver; if loose, insert insulating wedges at the loose points. Treat any areas showing blue heat marks.

●Slot Wedge Inspection: Check for looseness, breakage, or deformation of the slot wedges. Gently tap them with a small wooden hammer, ensuring there is no hollow sound. If more than one-third of a slot wedge is loose, replace it with an insulated wedge.

●Winding Insulation Inspection: Inspect the insulation at the ends of the stator windings for damage, overheating, or peeling of the varnish. Ensure the tie wires and blocks are not loose. Repair minor varnish issues by brushing with varnish. For severe cases, remove old varnish completely and reapply, or replace the winding. Secure any loose or broken tie wires.

●Lead and Terminal Box Inspection: Ensure that the insulation of the stator winding leads is intact. Rewrap if damaged. Ensure solder joints are firm with no cold solder joints or broken strands. Tighten all lead connections.

●Insulation Resistance Measurement: Measure the insulation resistance of the stator windings to determine if the insulation is damp or short-circuited. Repair any short circuits or grounding faults. If the insulation is damp, dry it using appropriate methods based on the specific conditions and site facilities.

2. Rotor Cleaning and Inspection

●Cleaning: Use clean compressed air at 0.2–0.3 MPa to blow off dust from all parts of the rotor. Clean oil stains with a cloth dipped in gasoline, and then wipe dry with a clean cloth.

●Core Inspection: Ensure the rotor core is tight and free from rust, damage, and overheating discoloration.

●Winding Inspection: For cage rotors, ensure the bars and end rings are secure with no cracks or looseness. Repair any welds or broken bars as needed. For wound rotors, perform similar checks as for the stator windings, and also ensure that the steel bands at both ends are secure, with no signs of looseness, displacement, breakage, overheating, or weld failure.

●Collector Ring and Brush Gear Inspection: For wound rotors, inspect and clean the brush gear and collector ring leads. Adjust brush pressure, polish the collector rings, and check the brush lifting device to ensure it operates smoothly and reliably.

●Fan Blade Inspection: Check that the fan blades are secure. Tap with a wooden hammer; a clear sound indicates good condition. Ensure the balance weights on the fan are secure and have not shifted.

●Shaft Sliding Surface Inspection: Ensure the sliding surface of the shaft is clean and smooth, with no damage, rust, or oval deformation.

3. Bearing Cleaning and Inspection

●Cleaning: Remove old lubricant from the bearings, clean with gasoline or kerosene, and wipe dry with a clean cloth. Ensure no brush bristles or cloth fibers are left inside the bearings.

●Bearing Inspection: Inspect cleaned bearings thoroughly. The inner and outer rings should be smooth with no scratches, cracks, or rust. The bearing should rotate freely without sticking, binding, wobbling, or axial play. Repair or replace if necessary.

●Bearing Clearance Measurement: Measure the clearance of sliding bearings with a feeler gauge, and the clearance of rolling bearings with lead wire. If the measured clearance exceeds specified values, repair or replace the bearings.

Sealing Inspection: Check the bearing cover, bearings, oil discharge gate, and shaft joints. Ensure seals are tight with no oil leakage.

As leading electric motor supplier in China,We provide electric motors from IE1 to IE5, certified to international standards, with reliable after-sales service. Let's elevate your business with our motors! 

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