Explore our leading industrial induction squirrel cage motors engineered for extreme environments, featuring international certifications including CE, NEMA, ATEX, and IECEx.
The modern industrial landscape relies heavily on electromechanical conversion systems. Among these, the three-phase induction squirrel cage motor represents the ultimate workhorse of global heavy industry. Powering over 60% of all industrial electrical loads, squirrel cage motors are fundamental to processes operating within oil and gas refineries, petrochemical complexes, thermal and nuclear power generation plants, water treatment facilities, and sub-surface mining operations.
As worldwide energy regulatory frameworks tighten—mandating shifts from IE3 efficiency to IE4 and IE5 classes—multinational procurement directors, EPC contractors, and plant engineers face complex challenges. Securing a reliable OEM supplier is no longer merely a transaction of sourcing physical motors. It requires verifying deep technical competency, strict compliance with regional explosion-proof certifications (such as ATEX, IECEx, CSA, UL, SABS, and TESTSAFE), and the capability to integrate digitalized, variable frequency configurations. Operating environments in modern processing industries demand absolute uptime, making motor reliability directly impact a plant's operational profitability and safety margins.
Shaanxi Nanfang Motor Technology Co., Ltd. serves as the officially authorized distributor of Wolong. Founded in 1984 and listed on the Shanghai Stock Exchange in 2002 (code SH600580), Wolong Electric Drive Group Co., Ltd. has established itself as an international leader in rotating machine manufacturing, drive controls, and power systems.
Through systematic global expansion and targeted technological acquisitions, Wolong has integrated several of the industry's most respected historic brands into a unified manufacturing and engineering network:
In 2011, Wolong acquired 97.94% of the ATB Group, positioned as one of Europe's top three motor manufacturers. This integration brought renowned subsidiaries into the Wolong system, including Morley—with a 130-year history of constructing heavy-duty flameproof motors for underground coal mining—and Laurence Scott, a pioneer in ultra-low starting current machines for nuclear plants and naval vessels. Following this integration, Laurence Scott was awarded the prestigious Queen's Award for Enterprise for three consecutive years.
The addition of Brook Crompton expanded Wolong's low and medium-voltage portfolios, reinforcing its position in high-efficiency industrial motors (including the premium 'W' and '10' series). Concurrently, the integration of Schorch (established in 1882) brought deep engineering expertise in high-power driving systems. Schorch designs are highly regarded in major global projects within petrochemicals, water management, marine defense, and heavy metallurgy.
In 2015, China's largest scientific research and manufacturing base for explosion-proof drives—Nanyang Explosion-Proof Group (CNE)—merged with Wolong. In 2018, Wolong acquired General Electric’s (GE) commercial and industrial motor division. This combined the historical engineering expertise of GE's heavy industrial division with Wolong's global production capacity, creating a comprehensive technological framework for hazardous area equipment.
The reliability of a squirrel cage motor under demanding electrical and physical environments depends on the design and quality of its internal components. Wolong leverages advanced design methods, including structural and fluid multi-physics simulations, to optimize performance:
The stator core is constructed using high-permeability, low-loss silicon steel laminations to minimize eddy current losses. The windings utilize high-grade polyester film reinforced with glass cloth and wrapped in low or medium-powder mica tapes.
Following assembly, the entire stator undergoes a comprehensive Vacuum Pressure Impregnation (VPI) process. This cycle extracts all microscopic air voids from the winding slots and infuses a solventless insulating resin. The resulting winding structure provides high dielectric strength, mechanical protection against thermal cycling stresses, and resistance to environmental moisture and chemical contamination.
For standard and high-efficiency low-voltage configurations, Wolong utilizes high-pressure centrifugal die-cast aluminum rotors. This process creates a single, integrated assembly comprising rotor bars, end rings, and cooling blades.
For high-voltage or heavy-duty starting configurations, fabricated copper bar rotors are employed. These feature oxygen-free copper bars inserted into the rotor slots and welded to the end rings using automated, controlled induction brazing. High-speed configurations also incorporate dynamic retaining rings to manage centrifugal forces during transient conditions.
The structural design of Wolong frames is developed using 3D Finite Element Analysis (FEA) and computational fluid dynamics (CFD) modeling. Manufactured from high-tensile cast iron or welded structural steel, the frames provide mechanical redundancy and vibration isolation.
Optimized cooling fins maximize convective heat transfer, maintaining a low temperature rise across the stator winding during continuous full-load operation. This thermal management helps preserve insulation life and extend maintenance intervals.
The ventilation system features an aerodynamically optimized fan cover body, an integrated air guide cylinder, protective screens, and acoustic silencer plates.
Air enters through side inlets to minimize path restrictions and reduce aerodynamic turbulence noise. Sound-absorbing lining materials damp high-frequency blade-pass noise, ensuring compliance with strict industrial noise regulations while maintaining an IP22 or IP55 ingress protection rating.
Different industrial applications present distinct operational hazards. Wolong customizes its squirrel cage induction motor lines to meet these specific challenges, ensuring compliance with global regulatory standards:
Refineries and petrochemical plants process volatile hydrocarbons, creating Zone 1 and Zone 2 hazardous areas. Wolong's explosion-proof motors (such as the YBX4 and YBX5 series) feature flameproof enclosures designed to contain internal explosions without igniting the surrounding atmosphere, compliant with ATEX and IECEx standards.
Underground coal mining requires robust construction due to mechanical impacts, moisture, and coal dust hazards. Wolong's Morley brand specializes in custom mine-duty flameproof motors that withstand high mechanical vibration and meet global mining electrical standards.
Thermal and nuclear power facilities require motors with high operating reliability. Leveraging Laurence Scott's design heritage, Wolong provides large high-voltage induction motors configured for low starting currents, minimizing voltage sags on weaker auxiliary supply grids.
To facilitate international deployment, Wolong maintains a comprehensive certification matrix. Our motors comply with international quality, safety, and performance standards:
Nemko / ATEX
CSA
CE Mark
CCC
SABS
TESTSAFE
ISO 9001 Quality Framework: All global manufacturing centers operate under certified ISO 9001 quality management systems. This ensures traceability of raw materials, process controls during winding and impregnation, and standardized routine testing.
NEMA Mechanical & Electrical Standard: For the North American market, Wolong's NSHE series complies with NEMA MG1 requirements. This includes standardizing shaft dimensions, frame mounting patterns, torque curves, and efficiency measurements verified under CSA and UL testing protocols.
TESTSAFE & SABS Approvals: Obtaining the Australian TestSafe and South African SABS certifications allows direct deployment of Wolong mining motors into high-barrier regulatory markets without requiring additional localized testing.
The electric motor industry is undergoing a transition driven by digitalization, material science, and efficiency regulations. Wolong's technical roadmap aligns with three primary industry trends:
While induction motors are approaching physical efficiency limits, Wolong is expanding research into Permanent Magnet Assisted Synchronous Reluctance Motors (PMaSynRM) and PM synchronous designs (such as the WEPM series) to deliver IE5+ efficiency profiles under variable speed operational cycles.
Integrating vibration and thermal sensors (such as OLI Ex sensors) directly onto the motor frame enables real-time data streaming. This data helps calculate remaining bearing life, detect stator phase imbalances, and schedule predictive maintenance before unplanned shutdowns occur.
Motors are increasingly paired with Variable Speed Drives (VSDs) to optimize process energy consumption. Wolong's insulation systems are designed to withstand high dV/dt voltage spikes generated by fast-switching IGBT converters, mitigating partial discharge hazards.
Browse our secondary selection of specialized rotating machinery, including variable-speed PMSMs, conveyor-specific drives, and high-temperature fire ventilation motors.
Contact Shaanxi Nanfang Motor Technology Co., Ltd. for engineering consultations, custom OEM specifications, and international project inquiries.
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