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.
This calculator was developed and verified by the Vibromera engineering team, makers of the Balanset portable balancing instruments.
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
Balance motors in the field and diagnose electrical/mechanical faults with professional instruments.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
