Free Engineering Tool
Motor Nameplate Decoder
Enter motor nameplate data and decode every field. Calculate synchronous speed, slip, efficiency, torque, and understand insulation class, IP rating, duty cycle, and frame size meanings.
Decoded Nameplate
Synchronous Speed
ns = 120 × f / p, where f is frequency (Hz) and p is number of poles.
Slip
s = (ns − n) / ns × 100%, where n is rated RPM. Typical slip: 2–5% for standard motors.
Torque
T = P × 9550 / n (Nm), where P is power in kW and n is RPM.
Efficiency
η = Pout / Pin = P / (√3 × V × I × cos φ). Can be estimated from nameplate data.
Insulation Classes
| Class | Max Winding Temp | Ambient + Rise + Hotspot |
|---|---|---|
| A | 105°C | 40 + 60 + 5°C |
| E | 120°C | 40 + 75 + 5°C |
| B | 130°C | 40 + 80 + 10°C |
| F | 155°C | 40 + 105 + 10°C |
| H | 180°C | 40 + 125 + 15°C |
IE Efficiency Classes (IEC 60034-30-1)
| Class | Level | Min. η (example: 11 kW, 4-pole, 50 Hz) |
|---|---|---|
| IE1 | Standard | 87.6% |
| IE2 | High | 89.8% |
| IE3 | Premium | 91.4% |
| IE4 | Super Premium | 93.3% |
| IE5 | Ultra Premium | ~94.6% (indicative) |
IE1–IE4 values are the nominal efficiency limits of IEC 60034-30-1:2014 for this one example rating (11 kW, 4-pole, 50 Hz) — limits differ for every power rating, pole count and frequency. IE5 was only informative in the 2014 edition (Annex A, ~20% lower losses than IE4); normative IE5 limits were introduced in IEC 60034-30-1:2025 — the IE5 figure shown is indicative.
IP Rating Explanation
IP stands for Ingress Protection. First digit = solids protection (0–6), second digit = water protection (0–9).
- IP55 — Dust-protected, protected against water jets from any direction
- IP65 — Dust-tight, protected against water jets
- IP66 — Dust-tight, protected against powerful water jets
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