Mention ‘holistic’ and ‘eco’ in the same sentence and people will think you are talking environmentalism or personal health, but the two concepts are becoming synonymous with modern motor control strategies.
CAPIEL (the European Coordinating Committee of Manufacturers of Electrical Switchgear and Controlgear)’s recent position paper on taking an eco-smart approach toward the use of premium efficiency motors – “Ecodesign requirements for Electric Motors – Towards a System-Approach” - stated that ‘Real-life energy efficiency can only be achieved through a system-approach. Both motor and its control node must match the intended application requirements’.
Motors of all sizes and uses often need large amounts of energy when required to quickly accelerate to full speed and both soft starters and variable frequency drives can be used to reduce inrush currents and limit torque. The decision to pick one, however, is decided by the application, system requirements, and cost implications. It requires a holistic approach.
Design of energy efficient systems requires the consideration of the drivetrain / conveyor / other systems as a whole. There is little point installing high efficiency motors and equipment if the entire system is fundamentally inefficient.
Using energy efficient components is important but selection of the correct motor control mode (fixed or variable speed) is also critical. This is important as the Regulation 640/2009/EC (Lot 11) calling for Electric Motor Efficiency can be misread to say that a less energy-efficient motor fitted with a VSD (say IE2 + VSD) is as efficient as a IE3 + Motor Starter setup.
Approximately 80% of motor applications are most efficiently operated at a fixed speed. Using a Variable Speed Drive (VSD) with such a system is hugely inefficient, regardless of the efficiency of the motor you are running.
An Energy efficient motor is just one piece in the energy-saving puzzle – changing nothing in a system other than introducing an energy efficient motor changes little to nothing.
A soft starter is the most efficient control solution for applications with a fixed speed and variable load1. Soft starters like AuCom’s new EMX4 can make a difference by:
- limiting inrush and using the right amount of energy for motor starting enables design of efficient distribution circuits and prevents breaker trip due to motor starting.
- precise control of the starting and stopping of IE3 motors. The EMX4 can control acceleration and deceleration to cater for motors with the tough torque curves.
To find out more about how you can take make the most of premium efficiency motors, download the AuCom brochure, ‘EMX4: redefining soft starters’.