Tuesday, April 4, 2017

Energy Savings with IE1, IE2 & IE3 Motors

Motors are part of every industry and commercial establishments and so it becomes very important to reduce the cost related to electricity to be reduced to as much as possible so as to increase profitability.
There are some important facts which you should must know about motors as per research done by International copper association India :-
(i)                  In industries motors usually accounts for 70% of power consumption

(ii)                In motors entire life major chunk i.e. 88% of total life cost is energy cost.

So it becomes very important to save electricity as much as possible as soon you reduce electricity bill you will save environment also.
So premium efficient motors are equally become very important as these motors has very low losses as these motor have used following for reducing losses:-
(i)                  Reduced stator copper losses as they have more active material
(ii)                Reduced iron losses by using high grade silicon steel
(iii)               Reduced friction and windage losses by using better fan design
There are following advantages of using Extra premium efficient motors over IE2 & IE3 motors:-

(i)                  Constant efficiency of motors from 60% of load to 100% of load
(ii)                Lower electricity consumption as losses are minimum , so power bill reduced
(iii)               These motors have greater ability to operate at higher temperature range.
(iv)              These motors have better thermal and electrical stresses
Indian Energy efficient Motors standard:-
Bureau of Indian standards introduced the standard for energy efficient motors in 1989 as IS:12615. This standard covers 4 pole with rating upto 37 KW.
Revision: I of IS:12615
Same was revised in 2004 to cover more motors this time standard covers :-
(i)                  2 Pole – 4 Pole Motors having rating from 0.37 KW to 160 KW
(ii)                6 Pole motors having rating from 0.37 KW to 132 KW
(iii)               8 Pole motors having rating from 0.37 KW to 110 KW
This revision also includes efficiency levels i.e. Eff1 & Eff2 and Test methodology for the same as per IEC 60034-2
Revision: II of IS:12615
In year 2011 same was again revised as Upon introduction of IEC 60034-30 for efficiency classification of induction motors and same was adopted by other countries. So in order to be in par with standard, standard was revisited and revised with following :-
(i)                  Motor range has been extended Now it will covers 2 Pole, 4 pole, 6 pole motors ranging from 0.37 KW- 375 KW.
(ii)                Motor testing standard should be IS:15999:2011 or IEC 60034-2-1
(iii)               New efficiency levels introduced: IE1, IE2 & IE3 (IEC 60034-30:2008)
(iv)              New parameters like Breakaway Torque, Current & full load current are included
How to find when to replace the motor?

There are following steps which you can follow in your industry to arrive at conclusion that whether we needed to replace motors or not:-
(i)                  Prepare database of all motors along with breakdowns in past.
(ii)                Prepare database for efficiency of motors as per motor name plate
(iii)               Takeout database of number of rewinding’s done in past.
(iv)              Checkout OEM data provided with motors about efficiency curves of motor and effects of every rewinding on motor efficiency. As per typical analysis for motors it has been found that for every rewinding there is drop in efficiency of motor form 1% to 5% for every rewinding.
From database we can also found that if motors are older than 8 to 10 years then definitely motors will be inefficient motors also over the period of time there might be rewinding of motors will be done which worse the inefficient motors.
It has been found that often repair/rewinding cost of medium and small motors (<50 KW) is often on higher side so it is often recommended to replace the same after certain period of time after complete analysis. 
After preparing all database checkout various efficient motors available in market and compare with your database. Now prepare a payback calculation sheet and you can definitely come out at some conclusion for replacement of motors.
Below cost benefit analysis of a typical 20 KW motor is done to strengthen viewpoint of replacement of medium and small size motors:-
Here loading of 80% is considered over whole year.
Running Hrs are taken as 20 Hrs per day and for whole year it will comes to be = 365 X 20 = 7300 Hrs
Annual Cost of energy for IE1 Motors= ((20* 0.8) X 7300 X 8)/ (0.887) = 1053438 Rs / Year
Annual cost of energy for IE2 Motors= (20*0.8) X 7300 X 8/ (0.906)= 1031346 Rs / year
Annual Cost of energy for IE3 Motors= (20*0.8) X 7300 X 8/ (0.921)= 1014549 Rs / year

Parameter
Standard Motor Eff2 (IE1)
Energy efficient Motor
(IE2)
High Efficient Motor (IE3)
Motor KW rating
20
20
20
Efficiency
88.7%
90.60%
92.10%
% Loading
80%
80%
80%
Running Hrs /Year
7300
7300
7300
Energy Cost/ KWH
8.0
8.0
8.0
So Annual Savings comes out to be

22092
38888
Purchase price of New Motor in Rs.
45000
55000
63000
Payback period

 5.4 month
5.6 Months

So from above we can see that there are huge savings in respect to energy bill with shifting from IE1 Motors to IE2 and IE3 motors.

Also there are saving even if we shift from IE2 Motors to IE3 Motors.