Motor Operating-Point Energy Comparison Worksheet
Compare electrical input energy for two documented motor efficiencies at one common shaft-output operating point and time segment. IE class limits are not treated as the actual efficiency of a specific motor.
Document one equal-output segment
Both efficiencies must apply to the same delivered shaft power,load,supply,temperature and operating conditions. For a varying duty profile,evaluate every supported segment with its own output,efficiencies and hours,then sum the energies outside this worksheet.
Input power A
Input power B
Electrical energy A
Electrical energy B
Energy difference A−B
Cost difference A−B
Loss energy A
Loss energy B
Delivered shaft energy
Equations implemented
| 数量 | Equation | Unit/boundary |
|---|---|---|
| efficiency fraction | η=η%/100 | 0<η≤1;both values apply at the stated operating point. |
| electrical input power | P在=P出去/η | kW;motor terminals on the documented test basis. |
| input energy | E在=P在h | kWh for one constant segment. |
| motor loss energy | Eloss=(P在−P出去)h | kWh;does not include external drive/system losses. |
| signed difference | ΔE=EA−EB | Positive only when B uses less input energy under equal output/hours. |
| cost difference | ΔK=ΔE·k | Entered cost units;no fixed currency or FX conversion. |
Current IEC scope
IEC60034-30-1:2025,Edition2 is the current standard for IE efficiency classes of line-operated,single-speed AC motors rated for sinusoidal50Hz or60Hz supply. Its public scope includes0.12kW to1000kW,50V through1000V,2/4/6/8 poles and specified continuous-operation,ambient and altitude conditions. It excludes power-drive-system efficiency and losses from supply harmonics,cables,filters and frequency converters.
The2025 edition replaced IEC60034-30-1:2014,introduced IE5 limits,new IE5 tables and revised interpolation coefficients. The former page continued to calculate from2014 tables,derived its own IE5 values and linearly interpolated efficiency percentages. Those are not valid substitutes for the current closed tables or interpolation rules.
IEC60034-2-1:2024,Edition3 is current and establishes test methods for determining losses and efficiency of mains-operated rotating machines. A class threshold or catalogue label cannot replace the actual efficiency,test basis and operating-point evidence required by this arithmetic comparison.
IEC TS60034-30-2:2016 separately addresses efficiency classes for variable-speed AC motors not covered by Part30-1. Its public introduction states that application selection depends on actual load/speed operating points and operating time,and that an efficient motor alone does not necessarily produce an efficient power-drive system.
Exact IE tables,interpolation coefficients,tolerances,test-method selection and regulatory mappings remain NEEDS_LICENSED_SOURCE. They are intentionally not reproduced or inferred by this worksheet.
已修正的内容
The former calculator treated IE minimum limits as actual motor efficiency,assumed rated output was delivered continuously,used linear interpolation between closed table rows,clamped every rating below0.75kW or above200kW to an endpoint,and used a derived “20% lower losses” IE5 table after normative IE5 values had been published.
The replacement removes all embedded IE tables,class selectors,pole-speed approximations,presets,defaults,URL/history persistence,hard-coded euros and unsourced1–4-year payback and legal-compliance claims. It accepts only documented efficiencies applicable to the same shaft-output segment and reports a signed comparison without recommending an alternative.
Evidence required for use
- Use efficiency values obtained or guaranteed on a comparable IEC60034-2-1 or other controlled test basis at the relevant load,supply,speed and temperature.
- Do not use nameplate IE class alone as η. A motor may exceed its class minimum,and part-load efficiency differs from rated-load efficiency.
- For variable load/speed,build a segment or time-series model using the applicable efficiency map and include converter and driven-system losses within the chosen boundary.
- For an investment decision,add installed cost,maintenance,downtime,service life,discounting,tax and uncertainty in a separate documented life-cycle model.
