This part of IEC 60034 specifies efficiency classes for variable speed rotating electric machines not covered in IEC 60034-30-1. The standard only applies to machines that: • have a rated power PN from 0,12 kW to 1000 kW; • have a rated voltage UN above 50 V up to 1 kV; • have a rated speed nN from 600 1/min up to 6000 1/min regardless of the number of magnetic poles; • are designed for cooling methods IC4A1A0 (IC410), IC4A1A1 (IC411), IC4A1A6 (IC416), or IC4A1A8 (IC418) or IC71W according to IEC 60034-6; • are capable of continuous operation at their rated operating point (torque/power, speed) with a temperature rise within the specified insulation temperature class; NOTE 1 – Most motors covered by this standard are rated for duty type S1 (continuous duty). However, some motors that are rated for other duty cycles are still capable of continuous operation at their rated power and these motors are also covered. Motors rated between S3 and S10 with a cycle time of 80% or more may be concerned. • are rated for any ambient temperature within the range of – 20 °C to + 60 °C; NOTE 2 – The rated efficiency and efficiency classes are based on 25 °C ambient temperature according to IEC 60034-2-1 and -2-3. NOTE 3 – Motors rated for temperatures outside the range – 20 °C and + 60 °C are considered to be of special construction and are consequently excluded from this standard. NOTE 4 – Smoke extraction motors with a temperature class of up to and including 400 °C are covered by this standard. • are rated for an operating altitude up to 4 000 m above sea level. NOTE 5 – The rated efficiency and efficiency class are based on a rating for altitudes up to 1 000 m above sea level.