Conforming to IS: 12615-2011 & IEC: 60034-30.
The new IS: 12615-2011 defines the following efficiency classes of low-voltage three phase
asynchronous motors in the power range from 0.75 kW to 375 kW.
IE1 = Standard Efficiency (comparable to EFF2) (only for variable frequency drive
IE2 = High Efficiency (comparable to EFF1)
IE3 = Premium Efficiency
IE4 = Super Premium Efficiency
The higher the efficiency class the higher is the complexity of motor production and the higher is the amount of material to be used (as for instance copper) & the motor price will increase accordingly. In relation to the motor life time the purchase price is only a few percentage points and due the saved energy cost the pay-back period is short. Although over a motors lifetime energy represents over 97% of its operating costs, the purchase of new motors is driven by price and not the energy it will consume. It is becoming clear that by investing a little more money on a high efficiency motor the investment can be paid back with energy savings.
Last updated on : 23 June 2018