ABB welcome new motor efficiency standard
INTERNATIONAL power and automation technology company ABB have welcomed the new IEC international testing standard for electric low-voltage motors, which will make it easier for users to save energy by selecting the right high-efficiency motors for their specific applications.
ABB have already started re-testing their motor range according to the new standard (IEC/EN 60034-2-1) and will publish the new efficiency values in their catalogues during 2008, as soon as the tests are completed.
‘We welcome the fact that the efficiency measurement standards for electric motors are becoming more harmonized worldwide,’ said Steve Ruddell, for ABB. ‘We have waited a long time for a level playing field to be introduced.’
The new standard will tighten up testing procedures and give manufacturers the opportunity to publish more accurate efficiency values. Manufacturers will also be required to state in their motor documentation how the values have been measured.
Unlike the old standard, which was partly based on estimated values, the new one is based on actual measured values of winding, rotor and additional load losses in the motor, giving more accurate results.
In particular, the new standard significantly tightens up the calculations of the additional load losses, which were previously estimated at 0.5% of the input power at rated load and often resulted in estimated total losses being too low.
Compared to other machines, electric motors are generally very efficient, typically 95% for a 90kW high-efficiency motor. But ABB say that with a large number of motors installed, even small changes in efficiency can make a big difference, as two-thirds of the electricity used in industry is used by electric motors.
Although high-efficiency motors (EFF1) normally cost 10–15% more than standard motors (EFF2), ABB say this price premium is quickly repaid by the resulting energy savings. According to the company, the purchase cost of a motor is only about 1% of its total life-cycle cost, with electricity being by far the greatest part of the overall cost.
