By Eamonn Ryan from a SAIRAC Cape Town presentation
At the SAIRAC Cape Town Tech Talk, Marthinus Greeff from WEG South Africa discusses the vital topic of motor efficiency, emphasising its growing importance globally and its impact on South Africa’s energy landscape. The session highlights the need for more energy-efficient motors, especially with the upcoming regulatory changes in South Africa. This is Part 4 of a seven-part series.
The SAIRAC Cape Town Centre January TechTalk. SAIRAC Cape Town Centre.
The transition to IE3 motors is expected to impact the pricing of fans, which are key components in systems like HVAC. While the cost increase is inevitable, Greeff assures the audience that the price difference between IE1 and IE3 motors will not be as significant as some fear. The market will still have reasonably priced, energy-efficient options for general-purpose applications.
Motor rewinding and efficiency losses
Greeff revisits the issue of motor rewinding, noting that while it’s often a cheaper option than replacing a motor, it leads to efficiency losses. Rewinding can cause a motor to lose up to 3% of its efficiency each time, especially if lower-quality materials are used or the process is done improperly. Over time, these efficiency losses accumulate, making rewound motors less energy-efficient and more costly to operate.
Efficiency vs cost
A key point Greeff emphasises is the balance between cost and efficiency. In South Africa, businesses with tight budgets may opt for cheaper, less efficient solutions like rewinding or using lower-efficiency motors. While these may appear to be cost-effective in the short term, they often result in higher long-term energy consumption. Greeff argues that investing in more efficient motors like IE3, despite their higher upfront cost, can lead to significant savings in the long run due to lower operational costs.
Looking ahead
Greeff summarises the key changes brought about by the new regulations. From June 2024, the minimum efficiency standard will be IE3, with exemptions for certain motor types. Importers have a 12-month window to clear out older stock, but after June 2025 the stricter controls will apply.
While these regulations bring challenges—particularly in sectors like smoke extraction and African export markets—there are also opportunities for greater energy efficiency and cost savings in the long term. Businesses must prepare for these changes to ensure compliance and navigate the evolving market dynamics.
Thoughts on pricing and transition
Greeff reassures the audience that the price increase for IE3 motors, while inevitable, will not be as severe as some might expect. His company is actively working to align their product range with the new IE3 efficiency standards while keeping prices manageable. The goal is to offer general-purpose motors—used widely in applications like HVAC, pumps, and fans—that are both cost-effective and energy-efficient.
He assures businesses that the transition to IE3 motors will not result in a drastic rise in costs, offering a feasible path toward more energy-efficient solutions without overwhelming the budget. Greeff promises to continue keeping the audience updated on pricing and availability as developments unfold.
Aerating IE3 motors
The topic shifts to motor aeration and whether the aeration capabilities used in IE1 and IE2 motors are applicable to IE3 motors. Aeration, which helps ventilate motors to improve efficiency and lifespan, can still be applied to IE3 motors, but only by up to 10%, which aligns with the practices for previous efficiency classes.
However, Greeff points out that one challenge with IE3 motors, particularly in the UK, is speed control. When speed-controlled, IE3 motors have sometimes encountered overheating issues, which has led to a preference for IE2 motors in applications requiring speed control. While he hasn’t yet tested newer IE3 models in this regard, Greeff remains optimistic about the potential for IE3 motors in specific applications like smoke fans, citing positive test results from 2018 in Spain with ABB drives.
