MechChem Africa

An SEW-EURODRIVE DRN electric motor range that fully meets the IEC 60034 electric motor standard (IEC standards) was recently introduced into South Africa. Norman Maleka unravels what this means for plant operators and equipment specifiers.

We are very well known as a supplier of gearboxes and geared motors, which we sell every day in every part of the world. But for over 85 years, SEW-EURODRIVE has also been manufacturing the electric motors that are integrated into our geared motor product range.

sew ie3 DRN Electric Motor“Our customers, however, still tend to see us as a gearbox-only specialists, often specifying our gearboxes for use with the IEC electric motors from other OEMs. While we are always happy to comply with customer-specific specification, we want them to know that there is an alternative. We have a new range of premium efficiency DRN electric motors that are built according to the global IEC standards, which makes them 100% interchangeable with any other electric motor built on this universal platform,” Maleka tells MechChem Africa.

The new DRN IEC motor is a standalone electric motor that is relatively new to the SEW-EURODRIVE range. “But the technology used is the same as that incorporated into our premium efficiency IE3 geared motor range. So the motor technology involved is far from new to us,” emphasises Maleka.

“But we fear we may have confused the market with acronyms such as IEC and IE3 without taking the time to unravel exactly what these terms mean and their advantages. So I would like to put a little context onto global developments of electric motor standards,” Maleka says.

The standardisation of electric motors and their associated efficiencies began in the USA and its National Electrical Manufacturers’ Association (NEMA), which still remains the dominant standard in the USA. NEMA was founded back in 1926 in order to enable consumers to select from a range of safe, effective, and compatible electrical products.

More recently, however, efficiency has become the driving force behind innovation and NEMA was first to champion energy efficient electric motors. SEW-EURODRIVE quickly started offering its modular DR motors in three efficiency levels: standard, high efficiency, and NEMA Premium® efficiency.

NEMA motor designs tend to be larger and heavier than modern European motors, though, so the IEC (International Electrotechnical Commission) electric motor standard is fast taking over as the preferred option outside of the US. IEC-approved electric motors and controls tend to be less expensive, more compact, inherently safe and they react far more quickly to overloads.

“The IEC 60034-30 electric motor standard, therefore, caters more to the international markets, while NEMA, although available elsewhere, applies mostly in the USA,” Maleka explains.

So what is an IEC electric motor? Generally speaking, any electric motor that is designed according to the IEC standard is associated with a set of codes that specify the mechanical dimensions (frame sizes 63 to 315), power ratings (0.37 to 375 kW), efficiency (high efficiency: IE2; premium efficiency: IE3; and super premium: IE4) as well as a host of other technical specifications such as ingress protection (IP) and insulation class ratings (A to H).

“So if a customer is using 45 kW IEC motor with a frame size of 225, any other brand of motor with the same frame size, power rating and the same associated set of IEC codes will do exactly the same job and have the same footprint and mounting arrangement,” Maleka points out. “By choosing an IEC standard motors, users are assured that identical replacement motors are readily available and quickly interchangeable,” he adds.

This makes the new DRN IEC range from SEW-EURODRIVE a universal electric motor offering that can be incorporated into any IEC-based drive train with any SEW gearbox. Read more...

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