In modern hydrocarbon processing, chemical synthesis, and mining infrastructure, hazardous gas and dust atmospheres present continuous risks. Industrial plants require electrical equipment engineered to minimize safety threats while maintaining peak operational efficiency. The transition from the traditional non-sparking Ex nA standard to the modern Ex ec (Increased Safety "ec") standard under IEC/EN 60079-7 marks a major evolution in electrical explosion protection.
Ex ec certification validates that a motor is designed for Zone 2 hazardous areas, ensuring that the machine will not produce arcs, sparks, or dangerous hot spots during normal operations or under specific abnormal conditions. Unlike heavy flameproof (Ex d) enclosures that contain internal explosions, increased safety motors prevent the generation of ignition sources entirely. This design yields lighter motor footprints, lower thermal coefficients, and improved mechanical efficiency, making them ideal for heavy-duty industrial applications.
Under current harmonized standards, ATEX directives, and the international IECEx system, the classification of motors operating in hazardous Zone 2 environments has been unified. The previous standard IEC 60079-15 (which regulated Ex nA motors) has been restructured. The protection level has been integrated into IEC 60079-7 as Ex ec (Equipment Protection Level - EPL Gc). This harmonization ensures rigorous testing of stator insulation systems, rotor cages, and overall dielectric strength to guarantee reliability and prevent ignition.
Shaanxi Nanfang Motor Technology Co., Ltd operates as the authorized global distributor of Wolong. Wolong Electric Drive Group Co., Ltd. was established in 1984 and listed on the Shanghai Stock Exchange in 2002 (code SH600580). Over three decades of development, Wolong has grown to operate 3 global manufacturing bases, 39 advanced factories, and 3 world-class R&D centers.
Focused on the research, development, and manufacture of motors and control systems, Wolong integrates global brand resources to lead the market in engineering, production, and worldwide sales.
We provide diverse explosion-proof certificates tailored to match specific industrial regulations across different global regions, guaranteeing smooth customs approval and plant commissioning.
With configurations up to IE3, IE4, and IE5 efficiency classes, our motors—including premium permanent magnet designs—help lower operational costs and reduce greenhouse emissions.
We supply a complete range of low, medium, and high-voltage AC motors designed to operate reliably in hazardous areas, heavy industries, and highly corrosive environments.
Wolong operates motor and drive control R&D centers in China, Europe, and Japan, supported by a central research institute in Shanghai. This structural network drives innovation in motor design, control systems, and efficiency performance.
Wolong's portfolio includes domestic Chinese brands like Nanyang Explosion alongside century-old global industrial brands: Brook Crompton, Morley, Laurence Scott, Schorch, and ATB. These brands provide specialized equipment for oil & gas, petrochemicals, and mining industries.
As an established manufacturer, Wolong's explosion-proof motors deliver performance, safety, and reliability in hazardous environments like petroleum plants, chemical refineries, and coal mines. Their product range is certified under international standards including ATEX, IECEx, and CU-TR.
Wolong has strategically acquired key international motor and drive manufacturers to strengthen its technical capabilities and expand its global market presence:
Wolong acquired 97.94% of the Austrian ATB Group (ATB Motor), one of Europe's top three motor manufacturers. This acquisition integrated the historical mining motor brand Morley (boasting nearly 130 years of underground coal mining expertise) and Laurence Scott (known for low starting current designs and nuclear power plant auxiliary systems).
Schorch, established in Germany in 1882, joined Wolong. Schorch specializes in heavy-duty drive systems for oil & gas, petrochemicals, power generation, and water management projects globally.
CNE (Wolong Electric Nanyang Explosion-Proof Group Co., Ltd.), China's research and production base for explosion-proof motors, integrated with the Wolong Group to expand its production capacity for high-voltage, high-efficiency explosion-proof drives.
General Electric (GE) Industrial Motors joined the Wolong Group, adding GE's manufacturing experience and product support in heavy industries like mining, metallurgy, water treatment, and materials processing.
Wolong partnered with OLI, a global manufacturer of vibration motors and Ex vibration sensors, to supply industrial vibrators for materials handling and sorting applications worldwide.
Brook Crompton Motors, a developer of energy-efficient motor designs, joined the group. Their product lines include the "W" and "10" series low, medium, and high-voltage AC motors designed for harsh environments.
Wolong Electric Drive Group maintains key product certifications to support international industrial distribution:
The stator coil is constructed from high-grade polyester film reinforced with glass cloth. We utilize low-powder mica tape with high mica content or medium-powdered mica tape to ensure strong dielectric performance.
After winding, the assembly undergoes a Vacuum Pressure Impregnation (VPI) process. This treatment eliminates air voids within the winding slots, protecting the stator against moisture, mechanical vibration, thermal degradation, and corona discharge in high-voltage configurations.
The rotor features a squirrel cage layout. Cast aluminum rotors are manufactured using centrifugal casting or high-pressure die-casting, forming a single integrated structure of rotor bars and end rings. This design provides structural integrity and reliable starting torque.
For high-power or high-voltage applications, copper bar rotors with welded end-ring joints are used. Additionally, high-speed models feature protective retaining rings to secure the rotor structure under centrifugal stress.
The motor frame is designed using digital structural and fluid multi-physics simulation platforms. This modeling ensures mechanical strength, balanced heat dissipation, and natural frequency margins to isolate structural vibrations.
Constructed from high-strength cast iron or structural steel, the frame is engineered to absorb mechanical shocks, minimize vibration levels, and reduce operational temperature rise to maintain the designated Ex temperature class (e.g., T3 or T4).
The cooling assembly consists of a fan cover body, an air guide cylinder, a protective window, and an integrated silencer plate. This lightweight structure is designed to minimize vibration.
The side-positioned air inlet bypasses rear obstructions to maintain airflow. Incorporating sound-absorbing materials, the assembly reduces acoustic emissions from the cooling fan. It carries an IP22 rating, preventing accidental contact with the rotating fan blades.
As a global developer of electric motors and drive systems, Wolong operates 39 manufacturing facilities and 4 R&D centers across China, Vietnam, the United Kingdom, Germany, Austria, Italy, Serbia, Mexico, and India.
Our motor designs are used in heavy-duty machinery including fans, industrial water pumps, compressors, and specialized engineering equipment. These systems support operations in major industrial sectors:
In oil refineries and gas processing facilities, Zone 2 areas are common around pipelines and transfer bays. Ex ec motors provide power for large centrifugal compressors, oil export pumps, and air-cooled heat exchangers. They prevent thermal and electrical sparking risks without the added weight and cost of heavy flameproof enclosures.
Our coal mining motors, certified under TestSafe and other international mining standards, drive coal shearers, armored face conveyors, exhaust fans, and slurry pumps. They are designed to withstand structural impact, vibration, and dust accumulation in underground and open-pit mining environments.
For municipal water treatment and maritime applications, our positive pressure and flameproof motors drive water pumps, wastewater mixers, and onboard auxiliary systems. They feature IP55/IP56 ingress protection to resist water damage and chemical corrosion.
The industrial drive market is shifting toward increased efficiency and digital system integration. Wolong's technology roadmap focuses on three main developments:
Integrating permanent magnet (PM) synchronous motor designs with Ex ec increased safety protection. These PM motors deliver high energy efficiency (IE5 and above) and remain compact, reducing carbon footprints in heavy continuous-duty applications.
Equipping Ex ec motors with wireless sensors to monitor vibration, bearing temperature, and winding insulation status. Real-time diagnostic data is transmitted to central control units, supporting predictive maintenance to minimize unplanned downtime in hazardous Zone 2 environments.
Optimizing motor designs for gas group IIC environments, including hydrogen production, storage, and transport systems. The engineering focuses on seal integrity, electrostatic discharge prevention, and low-temperature operation to ensure safety in clean energy applications.
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