Our learnings from over 200 retrofit energy efficiency projects

Wonder why we get more savings (8 to 30%) as compared to motor name plate efficiency values (2 to 8%) when you change them with IE5 efficiency motors? Here is our learning from over 200 such retrofit cases, the science & art behind it:

1. IE1 to IE5 Induction motors efficiency values are much closer at full load (or name plate as shown in the table) but at lower loading this difference is very high (as shown in the graph). IE5 efficiency motors have relatively flatter curve.

2. That’s why a thorough Motors Load Study is needed to understand operating efficiency values which are a function of nameplate efficiency, % loading, rewinding, constant vs variable loading, operating hours, tariff, belt, pulley or direct drive, VFD is there or not and finally the nature of load the motor is driving. This is the science part of it.

3. Such a thorough study results in characterizing all the motors into (INR or USD) per year and the savings that could be derived by retrofitting with IE5 efficiency motors.

4. A lot of art is also involved at this stage due to 3 reasons. First is predicting the operating efficiency in the given case, second and more importantly can we replace the belt drive by directly mounting the motors on the load and how (whether site conditions allow) and thirdly can we lower the motor rating and get benefitted by increasing the percentage loading as well?

5. Then we get the ROI & payback periods and finally prioritise. The short cut does not work, yes absolutely do not.

6. Another observation has been that the savings are pretty high with smaller motors and they gradually reduce as we move to higher sizes of the motors. However the prices of the motors (INR/KW) are high at lower KWs and low at higher KWs. So, both aspects compensate each other and finally we get similar ROI on various sizes of the motors.

7. IE5 efficiency motors come in many forms from different brands, mains frequency or higher frequency, permanent magnet type or other technologies, requirement of specific drives (VFD), their availability, prices, frame sizes, delivery times, duty level, type (S1/S2…) and so on. You need to choose the right one, the most optimum.

8. In many cases installations are not easy so finer & deeper shop floor skills are very much required.

9. Our take it retrofitting motors with higher efficiency motors is both it begins with science but finishes as an art. The science part of it demands white collar skills as well as experience while the art part requires good blue collar team. Thus it’s a nice cocktail.

10. That’s why we developed it as a Motor Retrofit Program in our company SEE-Tech Solutions Pvt. Ltd. while closely working with many OEMs. You can connect with us at eemotors@seetechsolutions.in

Enjoy learning…