6 Tips On How To Distinguish The Quality Of The Motors

There are many motor production enterprises, including three-phase asynchronous motors. And the quality and price are also different. Although China has long developed technical standards for motor production and design, many enterprises have adjusted the design of the motor according to the subdivision demand of the market, so as to form differences in the performance of the motor on the market.

A synchronous motor  is a very mature technology product, and the production threshold is also low. In the industrial chain developed region, small workshop-type electric machine factories can be found everywhere, but to achieve excellent motor performance, quality stability, or a certain scale of electric machine factory can be guaranteed.

Distinguishing the quality of electric motors, whether low or high voltage, involves a combination of looking at specifications, physical characteristics, and etc.

1. Check for Industry Certifications and Standards:

● Efficiency Ratings (e.g., IE3, IE4): High-quality motors, especially for industrial applications, will often meet or exceed international efficiency standards like IEC (International Electrotechnical Commission) IE3 (Premium Efficiency) or IE4 (Super Premium Efficiency). These ratings indicate lower energy consumption and better long-term operating costs. A motor with a good efficiency rating is typically built with better materials and more precise manufacturing.

● NEMA Standards (for North America): For motors in North America, look for compliance with National Electrical Manufacturers Association (NEMA) standards. NEMA sets benchmarks for performance, dimensions, and construction, ensuring reliability and interchangeability.

● ISO Certifications: Manufacturers with ISO 9001 (Quality Management System) certification generally adhere to rigorous quality control processes throughout their production.

2. Examine the Nameplate Data and Datasheet:

● Comprehensive Information: A high-quality motor's nameplate and accompanying datasheet will be clear, legible, and provide extensive technical information (e.g., horsepower, voltage, amperage, RPM, service factor, insulation class, enclosure type, efficiency, power factor). Missing or vague information can be a red flag.

● Service Factor (SF): A higher service factor (e.g., 1.15 or 1.25) indicates that the motor can handle occasional overloads without damage, suggesting robust design and materials.

● Insulation Class: A higher insulation class (e.g., Class F or H) indicates the motor can withstand higher operating temperatures, which is crucial for longevity, especially under demanding conditions.

3. Assess Physical Construction and Materials:

● Silicon steel sheet

Silicon steel sheet is an important part of the motor, together with copper wire accounts for the main cost of the motor, silicon copper sheet is divided into cold steel sheet and hot steel sheet, the country has long advocated abandoning the hot sheet, general scale enterprises have been using cold sheet for manufacturing, cold sheet performance can be reflected in the brand, generally using DW800, DW600,DW470, etc., The ordinary asynchronous motor is generally DW800, some enterprises use strip steel manufacturing motor, performance is obviously different.

● Bearing

Bearing is the carrier that bears the high-speed operation of the motor rotor. The quality of the bearing affects the running noise and fever of the motor.

● Core Length

The stator and rotor of the motor are made of silicon steel sheet. The length of the die casting and the tightness of the die casting have a lot of influence on the performance of the motor. The longer the length of the die casting of the iron core is, the tighter it is, the better the performance is. Some enterprises to shorten the length of the core or cut the price of silicon steel sheet to reduce the cost, the price of the motor is low.

● Casing

The shell bears the vibration and heat dissipation of the motor in the process of operation. Calculated by weight, the heavier the shell is, the stronger the shell is. Of course, the appearance design of the shell and the appearance effect of die-casting are important factors affecting the price of the shell.

● Full rate of copper wire groove

Copper wire groove full rate is the amount of copper wire consumption, the longer the core, and the more copper wire consumption will be, the higher the groove full rate, the more copper wire will be used, the copper wire is sufficient, the motor performance will be good, some production enterprises in the case of not changing the length of the core, reduce the stator groove shape, in order to reduce the copper wire consumption and reduce costs.

4. Review Quality Control Processes

Including machining accuracy of parts, rotor die-casting process, assembly process, insulation dip paint, etc., will affect the performance and quality stability of the motor, the production process of large-scale manufacturers is relatively strict in management, and quality is more guaranteed.

5. Evaluate Noise and Vibration (if testable)

● Smooth Operation: When running (if possible to test before purchase/installation), a high-quality motor should operate smoothly with minimal noise and vibration. Excessive humming, rattling, or noticeable vibration can indicate issues with bearings, rotor balance, or winding problems.

● Temperature Stability: Monitor the motor's temperature during operation. While some heat is normal, excessive or rapidly increasing temperature can be a sign of internal inefficiencies, poor cooling, or overloading.

6. Consider the Manufacturer's Reputation and Warranty:

Reputable motor manufacturers with a long history in the industry often have a track record of producing reliable products and investing in R&D.

Generally speaking, the motor is basically a product that pays for what you get. The quality of the motor with a large price difference will certainly be different. The main thing is to see whether the quality and price of the motor can meet the requirements of customers and suit different market segments.

The motor products manufactured by ZCL Electric Motor Technology have obtained the ISO9001 quality management system certification, passed the CCC/COC, China energy-saving product certification, and passed the certification certificates of CE/UL/IRIS/CAS and other European and American countries. The company strictly improves the quality and efficiency of motor products and services for users in strict accordance with the requirements of relevant product standards.