Electricity and Control May 2021

DRIVES, MOTORS + SWITCHGEAR

37 kW to 355 kW, to meet the needs of its customers across all sectors of industry. With this range, the company believes it will be able to make a significant impact in reducing energy usage most quickly. All sectors will benefit and the energy-intensive users, in mining, petrochemical, pulp and paper industries for example, will see the most substantial savings on energy usage and costs, immediately and over the lifetime of each motor. Design and material improvements The improvements that have been made to achieve the higher performance efficiencies in the IE4 motor include the use of C4 class laminations in the motor. C4 is a specialised silicon-based steel for high performance equipment and Steyn highlights that it has the added advantage that it allows for repair of the motor (should the need arise) to full efficiency. Further improvements have been made in the winding design and with the use of additional copper and other active materials which contribute to reducing losses. Both the rotor and the stator are optimised by design and precision machining of the air gap is a further factor in increasing efficiency. Other mechanical features also play a role. Steyn adds that the IE4 motors are sized to be fully and easily interchangeable with existing WEG motors and they are VSD compatible up to 690 V. He notes that the smaller the motor the bigger the improvements in efficiency in proportional terms, and vice versa, the bigger the motor, the smaller the improvements in efficiency over same sized IE1 or IE3 motors. For example, the replacement of a 110 kW IE1 motor driving a pump, with an IE4 motor, will see a 2.2% gain in efficiency, with the concomitant reduction in energy usage. The related cost savings can amount to thousands of rand per year, and hundreds of thousands of rand over the lifetime of the motor. With the multiplier effect of multiple motors – in farm irrigation, for instance, or on a mine site – the savings grow. Steyn points out that for first time buyers, it is important to look beyond the first price of a super premium efficiency motor to the longer term return on investment. Depending on the size of the motor and the application, by specifying an IE4 motor instead of an IE1 motor, end users will typically recover the cost difference within just a few months through energy savings, and will see a continuing return on investment thereafter. In addition, the use of IE4 motors can make a major contribution to optimising efficiencies in the overall energy system in industrial applications. For example, they can be combined with variable speed drives, which deliver in the region of 30% efficiency improvements compared to mechanical process control.

smart operational technologies, like the WEG Motor Scan Solution. With sensors incorporated onto the motor this provides for data from the motors and the equipment driven to be tracked and monitored. It may include monitoring of factors such as temperature, vibration, hours in use, speed and others. The data can be accessed on smart phone using Bluetooth or stored and accessed from the cloud. At present the WEG Motor Scan Solution provides for recording and trending of operating data. Steyn says the next step will provide for live monitoring to track performance of all motors and motor driven equipment in real time. This will feed into a motor fleet management system which will enable users to monitor conditions in the motors and take action on alerts or sudden changes in tracked measurements. Demonstrating energy efficiencies Zest WEG has set up a demo trailer to demonstrate to customers the comparative energy savings achievable in use of IE4 versus IE3 versus IE1 motors. (You can view Electricity + Control’s video of the demonstration on the Electricity + Control website: www.crown.co.za/electricity- control.) The demonstration shows, for example, an IE4 0.75 kW motor driving a fan, versus an IE1 0.75 kW motor driving At a glance  Motors are significant users of electricity, accounting for between 65 and 70% of electricity used in industry.  More energy-efficient motors can achieve a 3 to 5% reduction in electricity usage and deliver significant cost savings.  Zest WEG will roll out the new IE4 motors in a range from 37 kW to 355 kW, to meet the needs of its customers across all sectors of industry.

Smart technologies Performance efficiencies can be further fine-tuned using

Fanie Steyn, Electric Motors Manager at Zest WEG, demonstrates the difference in energy usage and costs between IE1 and IE4.

Electricity + Control MAY 2021

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