Motor energy savings calculator
Moving up an efficiency class costs more at purchase and less to run. This works out both sides for your own power, pole count, running hours and electricity price, and shows the year the two cross.
Energy Savings Calculator
Enter prices in your own currency — the result uses whatever unit you put in.
The black line plots cumulative savings minus the initial price premium. The year it crosses the dashed red line is the payback point.
Efficiency figures are the limit values set by the standards, at 50 Hz and for the pole count you select: IE3, IE4 and IE5 from grades 3, 2 and 1 of GB 18613—2020, and IE1 and IE2 from GB/T 32891.1—2016, which adopts IEC 60034-30-1. Values between the tabulated ratings are linearly interpolated, as the standard itself directs. A motor that meets a class normally tests a little above the limit, so a real installation tends to save slightly more than this shows. The price premium is a market estimate, not a quotation — ask us for the figure that applies to your rating.
What the payback figure leaves out
Only the motor. Not the cost of the outage that swaps it, not a drive if one goes in at the same time, and not the load itself — a pump throttled against a valve wastes more than any efficiency class recovers. The calculation also assumes the motor runs at its rating; at part load the curves separate differently, and a lightly loaded machine pays back more slowly than this shows.
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