8.1 Introduction:
Electrical power is the one of the major raw material for cement industry. The cost
of cement is contributed by electrical energy about to 17% to 23% of its total
manufacturing cost. Hence, power saving is one of the biggest area of cement
cost reduction. The electrical power is utilized in cement industry through
induction motors. 40% of electrical power is utilized though LT induction motors
which operate at low efficiencies (<96%) where as 60% of electrical power is
utilized through HT induction motors which operates at higher efficiency >96.5%).
The motor efficiency is a major concern for power saving which is continuous and
can be achieved through smart decisions.
Low efficiency motors are cheaper than higher efficiency motors because of more
copper consumption and better design aspects. Apart from manufacturing
material cost, motor efficiency depends on quality of manufacturing from
manufacturer to manufacturer. The initial low purchase cost of LT motors attracts
to buyer at the time of decision making because purchaser usually ignores
efficiency concern of the motor.
Indian government is actively doing energy conservation with the help of Indian
Standards as under on Efficiency of Motors:
- IS 325 : Implemented in 1978
- IS 8789 : 3 phase Induction Motors efficiency
- IS 12615:2004 : ff2: Improved Efficiency & Eff1: High Efficiency levels
- IS 12615:2011 : IE1 as standard efficiency
IE2 as High efficiency
IE3 as Premium efficiency - IS 12615:2018 : IE 4 as Super Premium efficiency
In year 2014, IS 325 is withdrawn & IS12615 is adopted for S1 duty motors
As per Quality control order by Gov. of India, Minimum energy performance standards
for line operated 3phase induction motors in India shall be IE2 class applicable
from 01st Oct 2017
ENERGY EFFICIENCT MOTORS: Now energy efficient motors are manufactured
in according to IS: 12615:2018 specifications for the industries where energy is
concerned. The following key parameters are followed while manufacturing the
standard induction motors:
i. The copper used for motor winding is of high purity more i.e. 99% purity or
more.
ii. The quantity of copper used in motor winding more by increasing conductor
diameter and ampere-turns as compare to standard motors which results to
lower winding losses.