IEC 60034-30-3 Ed. 1.0 b:2024 PDF

This part of IEC 60034 specifies efficiency classes for fixed-speed three-phase high-voltage cage induction motors in accordance with IEC 60034-1 that
• have a rated voltage exceeding 1 000 V, but not exceeding 11 kV;
• have a rated power from 200 kW to 2 000 kW;
NOTE 1 Motors with rated power above 2 000 kW are produced in such small numbers and are designed and produced with a focus on achieving an optimum efficiency anyway, even though fulfilling increasingly special requirements that assigning efficiency classes would be an additional effort without the result of any countable energy saving.
• have two, four or six poles;
• are rated for single-speed line-operation;
• are intended for direct-on-line starting at rated or at reduced voltage and rated frequency;
• are constructed to any degree of protection;
• are designed for cooling methods IC411, IC511, IC611, IC01 or IC81W;
• are capable of continuous operation at their rated operating point (torque/power, speed) with a temperature rise within the specified insulation temperature class;
NOTE 2 Most motors covered by this document 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.
• are rated for any ambient temperature or coolant temperature within the range of – 20 °C to
+ 60 °C;
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 document.
• are rated for an operating altitude up to 2 000 m above sea level;
NOTE 4 The rated efficiency and the efficiency class are based on a rating for altitudes up to 1 000 m above sea level.
• have a locked-rotor current Il at stand-still and supply with rated voltage and frequency before application of any IEC or agreed tolerance in the range Il / IN ≥ 4,5;
• are designed for a customer load torque during starting not exceeding an envelope with a minimum of 25 % of the rated torque at low speed and a square shape T ~ n2 up to a maximum load torque at full speed of 60 % of the rated torque in case of 2 pole motors or 100 % of the rated torque in case of 4 pole or 6 pole motors, respectively, (see Figure 1), After starting is completed, the load torque of 2 pole motors is increased to 100 % of the rated torque;
• have to accelerate an external moment of inertia as defined by the customer requirements not exceeding the values given in Table 1 considering all start up conditions defined in this document for not more than three consecutive starts from cold condition or two starts from hot condition, respectively;
• are designed for a minimum locked-rotor steady state supply voltage of at least 80 % of the rated voltage during starting.