AS 60034.12:2009 pdf free download – Rotating electrical machines Part 12:Starting performance of single-speed three-phase cage induction motors

AS 60034.12:2009 pdf free download – Rotating electrical machines Part 12:Starting performance of single-speed three-phase cage induction motors.
5.1 General
Motors designed according to this standard are classified according to subclauses 5.2 to 5.5.
5.2 Design N
Normal starting torque three-phase cage induction motors intended for direct-on-line starting, having 2, 4, 6 or 8 poles and rated from 0.4 kW to 1 600 kW.
5.3 Design NY
Motors similar to design N, but intended for star-delta starting. For these motors in starconnection. minimum values for ‘1 and T are 25 % of the values of design N, see table 1.
5.4 Design H
High starting torque three-phase cage induction motors with 4, 6 or 8 poles, intended for direct-online starting, and rated from 0,4 kW to 160 kW.
5.5 Design HY
Motors similar to design H but intended for star-delta starting. For these motors in star- connection, minimum values for T1 and T are 25 % of the values of design H, see table 4.
6 Design N requirements
6.1 Torque characteristics
The starting torque is represented by three characteristic features. These features shall be in accordance with the appropriate values given in table 1 or table 5. The values in table 1 and table 5 are minimum values at rated voltage. Higher values are allowed.
The motor torque at any speed between zero and that at which breakdown torque occurs shall be not less than 1,3 times the torque obtained from a curve varying as the square of the speed and being equal to rated torque at rated speed. However, for 2-pole motors with type of protection ‘e — increased safety’ having a rated output greater than 100 kW, the motor torque at any speed between zero and that at which breakdown torque occurs shall not be less than 1.3 times the torque obtained from a curve varying as the square of the speed and being equal to 70 % rated torque at rated speed. For motors with type of protection ‘e’, the three characteristic torques shall be in accordance with the appropriate values given in table 5
NOTE The factor 1,3 has been chosen with regard to an undervoltage of 10 % in reiation to the rated voltage at the motor terminals during the acceleration period.