Engineered for hazardous environments, heavy-duty processing, and high-performance industrial drives globally.
Three-phase induction AC motors are the undisputed workhorses of modern industrial infrastructure. Representing more than 60% of all industrial electrical energy consumption globally, these machines drive primary processes across petrochemical plants, mining conveyors, municipal water facilities, and energy generation sites.
As global industries commit to aggressive decarbonization targets, the demand for highly efficient, premium-insulated, and ruggedly designed induction motors has accelerated. Under international frameworks like the IEC 60034-30-1 standard, industrial users are transitioning rapidly from basic efficiency (IE1/IE2) to super-premium (IE4) and ultra-premium (IE5) efficiency levels, integrating permanent magnet technology and advanced variable frequency drives (VFDs) to minimize operational expenses (OPEX) and carbon footprint.
China has grown to become the world's most advanced hub for electric motor manufacturing. By combining integrated upstream material processing (high-grade silicon steel sheet rolling, pure copper refining, specialized stator insulation chemistry) with highly automated winding and VPI systems, Chinese manufacturers deliver unmatched engineering value.
Top-tier Chinese companies like Wolong have successfully integrated advanced Western motor engineering traditions with massive, high-throughput automated manufacturing bases. The result is a highly competitive, certified, and robust motor supply chain that satisfies both strict North American NEMA standards and European IEC specifications.
Bridging global industrial applications with Wolong Electric's unmatched electric drive engineering capabilities.
Shaanxi Nanfang Motor Technology Co., Ltd is the authorized distributor of Wolong. Wolong Electric Drive Group Co., Ltd was founded in 1984 and successfully listed on the Shanghai Stock Exchange in 2002 (code SH600580). Over more than three decades of strategic expansion, technology acquisition, and engineering innovation, Wolong has established 3 major manufacturing bases, 39 manufacturing plants, and 3 world-class research and development centers globally. Wolong is committed to a unified global brand strategy, maintaining engineering leadership in the research, design, process control, and delivery of motors and control systems across global markets.
Wolong's strength lies in its successful integration of legendary industrial brands, accumulating hundreds of years of engineering history.
Wolong successfully acquired 97.94% of the ATB Group, one of Europe's top three motor manufacturers. This acquisition integrated world-renowned brands like ATB, Laurence Scott, and Morley under the Wolong umbrella.
Morley Motors: With a 130-year heritage, Morley is a global benchmark for flameproof underground coal mining machinery, engineering high-spec, high-power, and extremely rugged mining drives.
Laurence Scott: Known for pioneering low-starting-current motor technology for nuclear power plants and designing generators for marine naval vessels. The company received the prestigious Queen's Award for Enterprise for three consecutive years.
Schorch: Founded in Germany in 1882, Schorch represents high-quality heavy-duty motor systems. They support massive global projects in oil and gas, petrochemicals, power generation, and water management.
Brook Crompton: With over a century of innovation in electric motor technology, Brook Crompton has pioneered energy-efficient designs. They supply a comprehensive range of low, medium, and high-voltage AC motors, including the iconic Brook Crompton "W" and "10" series for harsh environments.
2015 - Nanyang Explosion-Proof Group (CNE): China's largest scientific research and manufacturing base for explosion-proof motors joined Wolong. CNE's specialized motor portfolio is vital to oil, gas, coal, metallurgy, nuclear power, and defense fields.
2018 - General Electric (GE) Commercial & Industrial Motors: By acquiring GE's commercial and industrial motor division, Wolong absorbed GE's extensive manufacturing experience in heavy industrial sectors such as water treatment, cement, paper, and materials processing, solidifying its global presence.
Premium raw materials and advanced mechanical designs guarantee low vibration, quiet running, and maximum operational life.
Wolong rotors employ a classic squirrel-cage configuration. Cast aluminum rotors are produced using centrifugal casting or advanced die-casting techniques, ensuring molten pure aluminum fills the core slots uniformly to integrate the rotor bars and end rings. This ensures excellent torque profile symmetry and structural integrity.
For high-capacity, heavy-duty applications, copper bar rotors are used. Reliable bar securing methods and state-of-the-art end-ring welding guarantee durability. High-speed models also incorporate retaining protective rings to withstand intense centrifugal forces.
The stator windings are crafted using high-grade copper wires insulated with polyester film and reinforced with glass cloth. We utilize premium low-powder or medium-powder mica tapes with high mica content to achieve superior dielectric strength.
Stator units undergo a rigorous Vacuum Pressure Impregnation (VPI) process. This eliminates internal air voids and encapsulates the winding assembly in protective resin. The resulting stator provides excellent moisture resistance, high mechanical strength, thermal stability up to Class F/H, and superb electrical performance.
The motor enclosure is designed using structural and fluid multi-physics field computer simulations. This design utilizes high-strength cast iron (or alternative welded steel plates for custom large-frame machines).
Our frames offer high structural redundancy, excellent heat dissipation surfaces, and natural frequency isolation. These characteristics allow the motor to absorb high mechanical shocks, maintain low vibration levels, and minimize temperature rise under continuous load.
The low-noise ventilation system integrates a fan cover body, air guiding cylinder, protective window, and acoustic silencer plate. The compact and lightweight design is engineered to minimize vibration and damp energy-loss noise.
The side air-inlet design optimizes ventilation when obstacles are located close to the rear of the motor, preventing backpressure. Coupled with sound-absorbing lining materials, it lowers overall operating decibels. The hood is rated IP22, preventing accidental contact with the fan blades.
Ensuring trouble-free operation, environmental compliance, and smooth customs clearance in every market.
Sourcing large motors for critical processes requires absolute compliance with national electrical codes and hazardous area safety standards. Wolong has established a comprehensive global compliance system, securing major product certifications to support international projects seamlessly.
Nemko / ATEX
CSA
CE
CCC
SABS
TESTSAFE
Providing high-torque, explosion-proof, and variable frequency solutions for diverse industrial sectors.
Highly explosive environments require robust explosion-proof ratings. Wolong's positive-pressure (YZYKS) and flameproof (YB3, YBX4, YBX5) series motors drive chemical pumps, refinery compressors, oil pipelines, and offshore platform fans with certified safety and reliability.
Underground coal mines are characterized by extreme humidity, fine abrasive dust, and combustible gases. Our Morley-engineered mining motors, YBSD conveyor drives, and YBC coal shearer cutting motors provide high starting torque and durable thermal properties.
Centrifugal water pumps, ventilation blowers, and air compressors benefit from Wolong's variable frequency speed regulation (WEPM PMSM) motors and high-voltage YKK induction motors. These systems deliver efficient speed-torque control and low starting currents, helping power plants, maritime vessels, and water treatment utilities optimize efficiency.
Key technical criteria for engineering heads, procurement officers, and EPC contractors when sourcing 3-phase AC induction motors.
Choosing the correct enclosure rating (IP code) and cooling mechanism (IC code) is crucial for motor lifespan in harsh environments:
While IE3 remains the compliance baseline in many regions, purchasing IE4 induction motors or IE5 Permanent Magnet Synchronous Motors (PMSM) reduces lifetime electricity costs. For continuous duty applications (e.g., ventilation fans, processing pumps), the slightly higher initial procurement cost is often recovered in energy savings within the first year of operation.
Insulation breakdown is a primary cause of motor failures. Stators processed with Vacuum Pressure Impregnation (VPI) ensure the resin penetrates deep into the winding slots, creating a solid block. This design prevents coil movement, protects against moisture, and improves heat transfer from the windings to the cast-iron frame. Always verify that your supplier uses high-grade polyester film, mica tape, and VPI processing.
Using Variable Frequency Drives (VFDs) offers great energy savings but can introduce common-mode voltage, leading to shaft currents that damage motor bearings (fluting). For VFD-fed motors, ensure the manufacturer installs insulated bearings on the non-drive end or grounding rings on the shaft to bypass stray currents safely.
Common technical questions answered by our motor engineering and application team.
Ex d (Flameproof): The motor enclosure is designed to withstand an internal gas explosion. If gas enters the motor and ignites, the frame prevents the flame from escaping and igniting the surrounding hazardous atmosphere. It is typical for Zone 1 applications.
Ex e (Increased Safety): The design focuses on preventing any arcs, sparks, or dangerous hot spots during normal or overload conditions. It does not contain an internal explosion but uses high-grade insulation and clearance margins to prevent ignition sources from forming. It is often used in Zone 2 environments.
Vacuum Pressure Impregnation (VPI) replaces traditional dip-and-bake methods. The wound stator is placed in a vacuum chamber to remove air and moisture, and then high-pressure resin is introduced to fill all microscopic voids. This provides three main benefits: superior moisture and chemical resistance, high mechanical strength that prevents coil movement, and excellent thermal conductivity, lowering overall operating temperatures.
Cast aluminum rotors are popular because they are cost-effective, offer high structural integrity, and provide good torque characteristics for standard starting profiles. The die-casting process integrates the rotor bars and end rings into a single piece, eliminating mechanical joints. However, for high-capacity, high-torque, or high-speed applications, fabricated copper bar rotors are used because copper has lower electrical resistance, reducing rotor losses and improving motor efficiency.
IEC Standards: Used globally outside North America, IEC specifies dimensions in millimeters, frame designations based on shaft height (e.g., Frame 132M), and performance in kilowatts (kW).
NEMA Standards: Common in North America, NEMA specifies dimensions in inches, frame designations (e.g., Frame 256T), and power ratings in horsepower (HP). While equivalent motors can be cross-referenced, their mounting holes, shaft diameters, and heights differ, requiring adaptation plates or custom shafts for retrofitting.
Variable frequency drives (VFDs) can generate common-mode voltages that create electrical currents in the motor shaft. If these currents discharge through the bearings, they cause pitting and fluting, leading to premature bearing failure. To prevent this, we install insulated bearings on the non-drive end to break the electrical path, and ground the shaft using conductive microfiber rings on the drive end to route current safely away from the bearings.
Yes, but the motor must be specifically rated for VFD operation (inverter duty). At lower speeds, standard shaft-mounted fans lose cooling capacity. An inverter-duty explosion-proof motor uses a separate blower for cooling or is designed with a temperature rating that prevents overheating at low speeds. The VFD parameters must also be matched to prevent voltage spikes that could stress the insulation system.
A broad range of heavy-duty AC motors designed for mining, ventilation, and heavy industrial machinery.
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