Energy Efficiency Upgrade
Moving from IE3 to IE4 or IE5, or from induction to permanent magnet synchronous — argued from numbers rather than a general claim of "saves energy".
IE3 vs IE4 vs IE5
| Parameter | IE3 (YE3) | IE4 (YE4) | IE5 (YE5) |
|---|---|---|---|
| Efficiency at full load | 92–94% | 94–95.5% | 95.5–96.5% |
| Annual energy savings vs IE3 | Baseline | 5–8% | 15–20% |
| Payback period | — | 12–18 months | 18–24 months |
| Typical application | General industrial | Continuous duty | 24/7 heavy duty |
| Price premium vs IE3 | Baseline | +15–25% | +30–50% |
Under the Chinese national standard GB 18613—2020, grades 1, 2 and 3 correspond exactly to IE5, IE4 and IE3.
Run the numbers for your caseWhen is a permanent magnet motor the right answer?
Where the advantage actually appears
A permanent magnet synchronous motor needs no magnetising current, so it holds above 95% efficiency at low speed and light load, where an induction machine falls away noticeably. The gap is widest on cyclic duty — beam pumps, crushers and similar.
Power range
Around 200 kW is where the permanent magnet advantage over induction is most pronounced across the widest set of applications. Above roughly 10 MW, conventional synchronous machines still lead on efficiency, though permanent magnet designs compete on cost and lead time.
The risk to account for
Thermal demagnetisation is specific to permanent magnet machines. Standard NdFeB magnets have a working ceiling around 150 °C, so mining and oilfield installations running hot need either enhanced cooling or a high-temperature magnet specification.
Matching LEADGO series
TYC for general purpose, TYP for high torque, GTYP for high speed and DZTYP for low-speed direct drive cover the range of migration cases. See the product pages, or the full comparison in this article.
Want the payback period for a specific machine?
Use the selection tool and the energy calculator together