There’s just space left for a few words about intrinsic motor efficiency. Motor efficiency is classified in line with the IEC 60034-30 standard that was introduced in 2008 and updated in 2014 as IEC 60034-30-1. The motor efficiency classes are designated IE1, IE2, IE3, IE4 and IE5, with IE1 the least efficient and IE5 the most efficient. All AC induction motors placed on the market in the EU since 1st January 2017 have had to either meet the requirements of IE3, or of IE2 if they are equipped with a VSD.
The motors you already have may be in a lower category, so is it worth replacing them? The answer is almost certainly no. The more efficient motor will cut your energy bills, of course, but probably not by enough to offset the cost of the new motor over a realistic timescale. The situation is somewhat different, however, when a larger motor has failed, and the choice is between having it rewound and replacing it. Each case will need to be decided on its merits, but in these circumstances, installation of a new high-efficiency motor may well be justified. It’s worth noting that such a replacement may be covered by the ECA scheme discussed in relation to VSDs.
Just one small word of caution. The vast majority of motors in use today are induction motors, but to achieve ever higher efficiencies, motor manufacturers are now offering new types, including permanent magnet and reluctance motors. If you are contemplating replacing an older motor with one of these, it is essential to confirm the compatibility of the control system and, if one is fitted, the VSD.
Whether you previously knew it or not, a large part of your electricity bill is almost certainly for energy consumed by motors. A little time spent measuring and monitoring the performance of your motor estate can therefore pave the way for very significant savings, which you will be able to quantify and confirm by continuing your monitoring after putting in place your energy saving measures! And please don’t forget, that if you need further information or advice, Chauvin Arnoux is ready and willing to help.