Choices and Trends in the Application and Choice of Industrial Motors
Upgrading Industrial Systems: A Practical Guide to Efficient Motor Selection
In the realm of industrial automation, upgrading existing systems with more efficient motors can lead to significant improvements in performance and energy savings. A new guide offers valuable insights into the process, focusing on providing practical knowledge about motor selection for various applications.
The guide delves into the most commonly used motor types, including AC induction, synchronous, DC, and servo motors. It provides information on the performance of these motors, discussing the advantages and disadvantages in terms of torque, VFD compatibility, cost, energy efficiency, and application fit.
Torque and Speed Requirements
Motors must meet or exceed the required torque for the duty cycle (intermittent vs. continuous) of the application. AC induction motors typically provide robust torque for many applications, but servo motors maintain torque at high speeds (>1,000 RPM) better than steppers, which lose torque at high speed. Stepper motors suit moderate speeds (under 1,000 RPM) and predictable loads with high positional holding capability.
Application Fit and Load Characteristics
Servo motors excel when loads vary or are unpredictable and multiple axes require coordinated motion, essential for robotics or CNC machining. Stepper motors offer a cost-effective option for consistent, predictable load applications requiring point-to-point positioning. DC motors with brushes require maintenance, but they are suitable for applications where torque-speed characteristics and brush maintenance are acceptable.
VFD Compatibility and Speed Control
Modern applications favor motors designed explicitly for VFD compatibility to enable economical and precise speed control, replacing traditional two-speed motors or starters. VFD use also reduces inrush current and extends motor life under frequent start/stop cycles. However, some motors may not tolerate VFDs well without derating or special design considerations.
Cost and Maintenance Factors
Stepper motors often cost 20-30% less than servo motors, making them favourable if budget constraints are tight and loads are stable. Operating motors continuously near their service factor increases heat and wear, leading to premature failure, so selecting motors sized for continuous loads above service factor is economically better long-term. Brush maintenance is a cost and reliability consideration unique to brushed DC motors.
Energy Efficiency and Heat Dissipation
Energy efficiency depends on proper sizing, design, and duty cycle. Motors running continuously near or above their rated load generate more heat, reducing reliability and efficiency. Ambient temperature and thermal limits affect the motor insulation and lubricant life, so derating might be needed in harsher environments to ensure longevity.
Duty Cycle and Operational Environment
Intermittent duty may allow smaller, lower-cost motors; continuous duty demands robust torque and thermal ratings. Operating conditions such as frequent start/stop, shock loads, and temperature extremes influence motor type and protective components (e.g., brakes for safety or positioning).
The guide also offers insights from integrators and end-users on their practical experiences with these motor types. It provides examples of real-world applications that demonstrate the use of various industrial motor types, offering suggestions for designing new industrial systems with energy-efficient motors in mind.
In conclusion, the guide offers valuable takeaways for upgrading existing systems or designing new ones. It emphasises the importance of balancing application-specific torque and speed demands, load predictability, cost constraints, the need for precise control (via VFDs or servo systems), energy efficiency, and maintenance considerations. By making informed decisions based on real-world factors, industrial systems can be upgraded to be more efficient, reliable, and cost-effective.
[1] Motor Selection Guide, www.motioncontroltips.com
[2] Energy Efficient Motor Selection, www.industrialmotor.com
[3] Industrial Motor Comparison, www.industrialmotorcomparison.com
[4] Motor Selection for Harsh Environments, www.harshenvironmentmotors.com
technology plays a crucial role in the selection of motors for industrial applications, as modern motors designed for VFD compatibility allow for economical and precise speed control, extending motor life. The finance industry can benefit from energy-efficient motors due to their lower operating costs and longer lifespan, which translates to significant savings in the long run. The manufacturing industry, in particular, can leverage technology in motor selection to improve productivity and reduce waste, while the industry as a whole can benefit from more efficient motor usage in terms of energy savings and environmental impact.
