The new AMI series induction motors from ABB, ranging from 500 to 11,000kW, are constructed using a series of modular building blocks to provide a complete range of enclosures and cooling arrangements. This enables each motor to be delivered application-ready, without costly and unnecessary features. Available options include air-to-water and air-to-air cooling, as well as a weather-protected version. Protection classes range from IP24W to IP56.
The AMI series squeezes an extra 10% of power from each frame when compared to its predecessors, enabling users to opt for smaller, lighter motors for a given duty. In addition, standard models keep noise levels below 82dB(A), with some options reducing noise even further. Low vibration has also been a design priority for the AMI series. Less vibration reduces wear and tear, prolonging the life of the motor and surrounding equipment.
A 2-pole, stiff shaft rotor design is available for motors that will ultimately be controlled by variable speed drives. This ensures that the motor can operate at any and all speeds within its 0 – 4000rpm range; because it’s first critical speed (the speed at which a motor starts to resonate) is higher than the maximum running speed of the motor. In addition, low levels of vibration in the bearing housing enable AMI motors to meet the latest IEC and NEMA standards, as well as API and most similar specifications.
The motors have form-wound windings featuring ABB’s Micadur Compact Industry Insulation System insulation class F (155oC). The Micadur system involves insulating the motor’s windings and connections with Mica-based tape. With the windings in place, the whole stator is impregnated with a high-temperature varnish using a vacuum pressure impregnation process. This provides effective insulation that boosts the reliability and life of the motor.