Induction motor efficiency standards

In 1997 18 motors of 11, 55 and 75 kW have been tested in the laboratory of the Electrical Engineering department at the KULeuven. Special attention was given to the various standards, mainly IEC 60034-2 and IEEE 112 Method B. The aim was to compare the various motors, and to rank them according to their efficiency. Based on these measurements, it was determined that the present IEC standard is not reliable, and does not offer the possibility to the consumers to make an instructed choice. The reason for this is the fact that the additional load losses, formerly refered to as stray load losses, are not properly taken into account. Comments on the new proposed IEC 61972 standard are included.