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 5 of a seven-part series.
The SAIRAC Cape Town Centre January TechTalk. SAIRAC Cape Town Centre.
Another key concern is the physical compatibility of new IE3 motors with existing systems, particularly their dimensions. Greeff assures the group that for the past decade, his company has ensured their IE3 motors maintain the same mounting dimensions and shaft sizes as the older IE1 motors. This guarantees that replacements can be made without major system modifications.
Although some newer motor designs might be slightly longer, the critical mounting dimensions—such as the feet and shaft—will remain unchanged. Greeff acknowledges that discrepancies could arise, but the company will provide accurate drawings and specifications to ensure smooth replacements and maintain system compatibility.
Challenges with Non-Standard Motors and Local Regulations
Greeff also addresses issues with non-standard motors, such as pad-mounted motors, which can sometimes have mismatched bolts or mounting holes. The lack of specific standards from the South African Bureau of Standards (SABS) for these motors creates occasional complications. Nevertheless, Greeff and his team are working towards greater standardisation for IE3 motors to avoid problems when replacing older motors with newer, more efficient ones.
Smoke fan regulations and certifications
The future of smoke fans, especially regarding the new IE3 regulations, is a major point of concern. Greeff critiques the idea of requiring IE3 motors for smoke fans, as this would necessitate retesting all fans globally. The retesting process could cost up to R200 000 per test and would make fans with IE2 motors non-compliant. If a motor type change occurs, such as moving from IE2 to IE3, the fan would require full re-certification, adding significant costs and complexities for manufacturers.
This situation is particularly worrying for South Africa, where the local market may struggle to adapt due to the high costs of testing and the limited time for compliance. Greeff highlights that if IE2 motors become obsolete for smoke fans, it could create serious disruptions for businesses that rely on these fans for fire safety and other critical applications.
The local content challenge
A local content issue raised by one attendee is the experience of the City of Cape Town, which faced complications importing motors for a system upgrade due to local content regulations from the Department of Trade, Industry and Competition (DTIC). These stipulations led to project delays, as motors that were imported couldn’t be used because they didn’t meet the required local content percentage. Greef sees potential for similar challenges with the new IE3 regulations, particularly when it comes to retrofitting and upgrading existing equipment.
Implications for the SA market
Greeff then discusses the challenges South Africa may face if the local market must comply with international IE3 standards, particularly regarding the retrofitting of existing equipment like smoke fans. The costs of testing and re-certifying equipment could be substantial, making it difficult for companies to stay competitive and maintain efficiency in the long term.
Motor efficiency and nameplate data
The conversation shifts to the importance of understanding a motor’s nameplate, which contains essential data about its efficiency at various load levels (e.g., 100%, 75% and 50%). This information is critical for determining how the motor will perform under different operating conditions. Greeff notes that while motor efficiency generally decreases as the load decreases, his company has been working on developing motors with a flatter efficiency curve. This means the motor will continue to perform efficiently even at partial loads, which is typical in systems like fans, where full load operation isn’t always necessary.
He also compares some IE3 motors to those marketed as IE3 but found to operate at IE1 efficiency levels. This discrepancy highlights the importance of checking actual performance data against marketing claims to ensure that a motor truly meets the required standards.
