Type test of motor
Through a series of extreme and even destructive environmental and durability tests, the survivability and performance margin of the motor are comprehensively verified.
1.Vibration Test
Objective: To evaluate the running stability and dynamic balance quality.
Impact: Accelerates bearing wear, shortens lifespan, generates noise, and causes loosening of connecting parts leading to secondary faults.
Reason: Mechanical (poor dynamic balance, improper assembly) or electromagnetic (uneven air gap, asymmetric magnetic circuit) imbalance.
2. Partial Discharge Testing
Objective: To evaluate the manufacturing quality of the insulation system of high-voltage motors and detect internal defects.
Impact: The insulation performance gradually deteriorates and eventually leads to breakdown and burnout.
Reasons: Insulation material defects, poor potting process, insulation damage or concentrated electric field.
3. No-load Test
Objective: To obtain basic performance parameters such as efficiency and power factor, and to reflect the design and assembly quality.
Impact: Excessive losses, low efficiency, high energy consumption, and excessive temperature rise.
Reasons: Improper magnetic circuit design, poor core material, and poor manufacturing process (laminated, air gap, winding).
4. Voltage Withstanding Test
Objective: To test the ability of the insulation structure to withstand overvoltage, which is a core safety test.
Impact: Insulation breakdown due to grid fluctuations, lightning strikes, or operational overvoltage, resulting in burnout, shutdown, and even safety accidents.
Reasons: Inappropriate insulation materials, defective insulation processing techniques, insulation damage during manufacturing, moisture or contamination.
5. Fan Performance Test
Objective: To verify the performance of the cooling fan and ensure sufficient airflow to control temperature rise.
Impact: Insufficient heat dissipation, excessive temperature rise, insulation aging, shortened lifespan.
Reasons: Poor design of the fan or air path, poor quality of the fan material or manufacturing process.
7. Noise Test
Objective: To evaluate the environmental indicators of the comprehensive design and manufacturing quality of the motor.
Impact: Noise pollution, and it usually indicates the presence of potential mechanical or electromagnetic issues.
Reason: Electromagnetic, mechanical (bearings, dynamic balance) or aerodynamic factors.
8. Short-term Voltage Rise Test
Objective: To test the motor’s ability to adapt to voltage fluctuations in the power grid.
Impact: Core saturation, current surge, overheating, abnormal vibration.
Cause: Insufficient electromagnetic design margin.
9. Insulation Resistance Test
Objective: To quickly assess the overall condition of the insulation system and determine if there is any moisture, aging, etc.
Impact: Decrease in insulation performance, increased risk of leakage or short circuit.
Reason: Moisture, contamination or aging of the insulation.
10. Shaft Voltage Test
Objective: To detect harmful shaft voltages that may corrode the bearings.
Impact: Shaft current causes corrosion of the bearings, leading to premature failure.
Reasons: Asymmetric magnetic circuit, common-mode voltage of the inverter, or internal static electricity of the motor.
11. Rotor Temperature Measurement
Objective: To verify the heat dissipation design, monitor the actual temperature of the rotor, and prevent overheating damage.
Impact: Overheating of the rotor can cause damage to the windings or breakage of the bars or rings.
Reason: Insufficient cooling, excessive loss, or overload.
12. DC Resistance Measurement
Objective: To check the manufacturing quality of the windings and the three-phase balance.
Impact: Unbalanced three-phase current, causing vibration, loss and overheating.
Reason: Incorrect wire gauge, incorrect number of turns, or poor internal wiring.
13. Purpose of High and Low Temperature Humidity Cycling Test
To evaluate the reliability of the motor under extreme climatic conditions.
Impact: Decreased insulation, material cracking, rusting, jamming, etc.
Reasons: Poor material weather resistance, poor sealing, mismatch in thermal expansion and contraction.
14. Salt Spray Test
Objective: To evaluate the corrosion resistance of the enclosure and coating.
Impact: Premature rusting, which affects structural strength and protection level.
Reason: Inappropriate material or surface treatment process.
Motor Predelivery test
100% comprehensive inspection. Through rapid online testing, the detection of key electrical safety and basic performance parameters is carried out to eliminate random defects during the manufacturing process.
1. Sensory inspection (scraping, rubbing, abnormal sounds, etc.)
Objective: To quickly check the assembly quality and obvious mechanical/electrical faults.
Impact: Indicates the presence of potential faults, which may lead to early damage. Reason:
Scraping and rubbing: The stator and rotor rubbing against each other (uneven air gap), skewed bearings, friction between the fan and the wind cover.
Abnormal electromagnetic noise: Local short circuit of the winding, loosening of the core, excessive harmonic components.
Resonance: External structural components not tightened, resonating at specific frequencies.
Stagnation: Poor lubrication of the bearings, damage or presence of foreign objects inside.
2. Stall Test
Objective: To measure the short-circuit impedance parameters and verify the winding design to ensure the starting performance.
Impact: Insufficient starting torque or starting current, unable to drive the load normally.
Reason: There is a deviation between the winding parameters (resistance, leakage reactance) and the designed values, such as incorrect number of turns or processing errors in the slot shape.
3. Other mandatory inspection items
No-load testing, withstand voltage testing, DC resistance testing, and insulation resistance testing are also mandatory inspection items at the factory.
Post time: Dec-11-2025