IEC 60034-12:2007 specifies the parameters for four designs of starting performance for single-speed three-phase 50 Hz or 60 Hz cage induction motors in accordance with IEC 60034-1. These specifications include:
- A rated voltage up to 1,000 V;
- Designed for direct-on-line or star-delta starting;
- Rated based on duty type S1;
- Constructed to any degree of protection.
The standard also applies to dual voltage motors provided that the flux saturation level is the same for both voltages and to motors having type of protection ‘e – increased safety’ with temperature classes T1 to T3 complying with IEC 60079-0 and IEC 60079-7.
NOTE 1: It is not expected that all manufacturers will produce machines for all four designs. The selection of any specific design in accordance with this standard will be a matter of agreement between the manufacturer and the purchaser.
NOTE 2: Designs other than the four specified may be necessary for particular applications.
NOTE 3: The values of torque and apparent power given in this standard are limiting values (that is, minimum or maximum without tolerance), but it should be noted that values given in manufacturers’ catalogues may include tolerances in accordance with IEC 60034-1.
NOTE 4: The values tabled for locked rotor apparent power are based on r.m.s. symmetrical steady state locked rotor currents; at motor switch on there will be a one-half cycle asymmetrical instantaneous peak current which may range from 1,8 to 2,8 times the steady state value. The current peak and decay time are a function of the motor design and switching angle.
