Three‑Phase High‑Voltage Modular Induction Motor AMI 450L12A, 280kW‑450kW, 12 Poles, 6000V, Suitable for Fan, Pump, Blower, Compressor and Mill

The ABB AMI 450L12A is a medium-frame modular high-voltage squirrel-cage induction motor developed on ABB’s proven AMI product platform, with rated power ranging from 280kW to 450kW. Adopting a 12-pole design, it has a synchronous speed of 500rpm, standard rated voltage of 6000V and 50Hz frequency. Designed and manufactured in compliance with IEC and NEMA international standards, this welded steel-plate motor is engineered for S1 continuous heavy-duty operation. It is normally equipped with IC611 air-to-air closed cooling and IP55 protection grade. Benefiting from its modular mechanical design, cooling units, condition monitoring sensors and auxiliary assemblies can be flexibly configured to adapt to diverse heavy-duty industrial environments. It is widely used to drive fans, pumps, blowers, compressors and grinding mills in cement, mining, water conservancy and petrochemical industries.

Core Technical Parameters 

Electromagnetic performance is optimised by multi-working-point finite element simulation, specially tuned for the low-speed high-torque load characteristics of 12-pole motors. It can cope with long-term continuous operation and fluctuating load cycles commonly seen in fans, pumps, blowers, compressors and grinding mill systems. The stator core is stacked with premium low-loss silicon steel laminations to reduce iron loss, stray loss and magnetic leakage under both full-load and partial-load operating conditions. Stator windings adopt high-grade corona-resistant magnet wire and go through complete VPI vacuum pressure impregnation treatment. The reinforced winding-end structure enhances mechanical rigidity, dielectric strength and resistance to electrical ageing, which enables the motor to withstand industrial grid voltage fluctuations and repeated starting impact from process equipment. The rotor adopts a heavy-duty copper-bar squirrel cage structure, featuring high mechanical stiffness, low rotor losses and stable starting torque output. Each rotor assembly undergoes multi-stage high-precision dynamic balancing to control vibration and noise strictly within IEC limits, satisfying the long-term stable operation demands of various low-speed heavy-load machinery.

The welded modular steel-plate frame is a key feature of the ABB AMI series, supporting flexible matching of cooling systems and auxiliary accessories according to different site environmental conditions. The AMI 450L12A is fitted with standard IC611 air-to-air closed cooling system. Two independent air circuits are arranged inside the motor: internal hot air circulates within the sealed frame and transfers heat to external ambient air through the top-mounted air-to-air heat exchanger. The IP55 enclosure provides reliable protection against dust ingress and water splash, making it applicable for dusty and humid industrial sites where open-ventilated motors are prone to faults. For locations with poor ambient air quality or insufficient heat dissipation capacity, the IC81W air-to-water cooling option can be selected to improve heat exchange efficiency.

The bearing system is customised for 12-pole low-speed heavy-load operating conditions of fans, pumps and mills. Heavy-duty rolling bearings are standard for this frame size, while sliding bearings can be supplied for the upper power range or working conditions with obvious impact and vibration loads. PT100 temperature sensors can be factory-preinstalled in stator windings and bearing housings, transmitting real-time temperature data to the plant DCS system for remote condition monitoring and overtemperature protection. Space heaters are available as an option to prevent winding condensation when the motor remains on standby. For variable-frequency energy-saving retrofit projects, an IC616 cooling variant can be provided to guarantee adequate cooling airflow under low-speed variable-frequency operation. Customisation options include ATEX explosion-proof modification, high-altitude adaptation, tropical anti-humidity and anti-corrosion coating, special terminal box layout and double shaft extension to meet complex project specifications.

Typical driven equipment includes industrial fans, circulating water pumps, process blowers, heavy-duty compressors and grinding mills. The motor supports direct-on-line starting or high-voltage soft starter starting, subject to the short-circuit capacity of the on-site power grid. Before shipment, every motor undergoes comprehensive factory acceptance tests, including insulation resistance test, power-frequency withstand voltage test, no-load running test, efficiency verification, vibration and noise measurement. Built on ABB’s mature AMI modular platform, AMI 450L12A delivers stable and dependable continuous operation, convenient spare parts interchangeability and low life-cycle cost for a wide range of heavy industrial applications.