In Cranes and Hoists S4 or higher duty motors are recommended, due to intermittent operations. IS 12615 - 2011 : states the following  where it is particularly mentioned– “that the IE3 is not recommended for s2, s4 duty motors.” As per IS 12615 (IS for Energy Efficiency Motors) Energy Efficiency motor can only be given for continuous duty motor ( S1 Duty ) and not applicable for intermittent duty motor i.e. S2, S4. Please refer to the exact point no. 8 ( Duty & Rating ) of IS 12615 as under “8: DUTY AND RATING The motors shall be rated for duty type S1 (continuous duty) as specified in 4.2.1 of IS/IEC 60034-1 or S3 (intermittent periodic duty) with a rated cyclic duration factor of 80 percent or higher.    The extract is reproduced here The motors shall be rated for duty type S1 (continuous duty) as specified in 4.2.1 of IS/IEC 60034-1 or s3 (intermi8ttent periodic duty) with a rated cyclic duration factor of 80 percent or higher. This standard shall not be applicable to the motors with duty cycles S2, S4 and above. When an equivalent S1 duty is specified by the driven equipment manufacturer and in case equivalent duty (power) lies between two specified power ratings given in Tables 1,2 and 3, the efficiency value shall be calculated using the formula given in 17.4.   Further IS 12615 - 2018 : also states that : that the standard is for the s1 duty motors only    Most motors covered by this standard are primarily rated for duty type S1 (continuous duty). Motors rated for duty cycles S2 and above with an equivalent S1 duty are also covered. These motors must also be marked with the equivalent S1 duty output and its corresponding IE class. Declaration of S1 duty output value may be as per mutual agreement between motor manufacturer and customer.   So for Crane Duty Application Energy efficient motors IE3 are not applicable.    We further recommend to use VVVF Drives for saving energy. As in this case the current is drawn equivalent to the load being handled, hence energy is saved every time a lower laid is lifted.