How does the calculator compute input power in three-phase mode?

It uses the formula P_in = √3 × U × I × cosφ, where U is line-to-line voltage, I is line current, and cosφ is the power factor.

What losses are included in the loss breakdown option?

It accounts for stator copper loss, iron (core) loss, rotor copper loss, mechanical (friction and windage) loss, and stray load loss.

Can I calculate efficiency if I only know the direct input and output power?

Yes, set the input mode to 'Direct' and disable the loss breakdown to enter P_in and P_out directly.

What is the difference between single-phase and three-phase electrical modes?

Single-phase uses P_in = U × I × cosφ, while three-phase incorporates the √3 multiplier for line-to-line calculations.

What unit should be used for power inputs and losses?

All power inputs, output power, and individual losses must be entered in Watts (W).

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Motor Efficiency Calculator (η = P_out / P_in)

Compute motor efficiency η = P_out / P_in. Supports electrical input (single-phase U·I·cosφ or three-phase √3·U·I·cosφ) or direct P_in; output power can be derived from a loss breakdown (copper+iron+rotor copper+mechanical+stray) or supplied directly.

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2 examples

Three-phase electrical: U=400, I=15, cosφ=0.85, P_out=8000 W → η≈77.0%

P_in = √3·400·15·0.85 ≈ 8833.46 W. η = 8000 / 8833.46 ≈ 0.9056 → 90.56%. (Losses = 833.46 W.)

{"result":"Motor efficiency, electrical three-phase. P_in = √3·U·I·cosφ = √3·400·15·0.85 = 8833.4591 W. P_out = 8000 W (direct). Losses = P_in − P_out = 833.4591 W. Efficiency η = P_out/P_in = 0.9056 (90.5591%).","metadata":{"input":{"powerInputMode":"electrical","phase":"three","voltage":400,"current":15,"powerFactor":0.85,"pout":8000,"useLosses":false},"result":{"inputPower_W":8833.4591,"outputPower_W":8000,"totalLosses_W":833.4591,"efficiency":0.9056,"efficiencyPercent":90.5591}}}

Direct P_in=10000 W + loss breakdown → P_out=8850 W, η=88.5%

P_in = 10000 W direct. Losses = 500 + 200 + 300 + 100 + 50 = 1150 W. P_out = 10000 − 1150 = 8850 W. η = 8850 / 10000 = 0.885 = 88.5%.

{"result":"Motor efficiency, direct input. P_in = 10000 W. Loss breakdown: stator copper 500 + iron 200 + rotor copper 300 + mechanical 100 + stray 50 = 1150 W. P_out = P_in − losses = 8850 W. Efficiency η = P_out/P_in = 0.885 (88.5%).","metadata":{"input":{"powerInputMode":"direct","pin":10000,"useLosses":true,"copperLoss":500,"ironLoss":200,"rotorCopperLoss":300,"mechanicalLoss":100,"strayLoss":50},"result":{"inputPower_W":10000,"statorCopperLoss_W":500,"ironLoss_W":200,"rotorCopperLoss_W":300,"mechanicalLoss_W":100,"strayLoss_W":50,"totalLosses_W":1150,"outputPower_W":8850,"efficiency":0.885,"efficiencyPercent":88.5}}}

Inputs

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14 options

SettingsAdjust formats, ranges, numbers, and modes.13

Power Input ModeselectOptionalPhaseselectOptionalOnly used in Electrical mode.Voltage U (V)numberOptionalRequired in Electrical mode. Line-to-line voltage for three-phase.Current I (A)numberOptionalRequired in Electrical mode. Line current.Power Factor cosφnumberOptionalRequired in Electrical mode. 0 < cosφ ≤ 1.Input Power P_in (W)numberOptionalRequired in Direct mode. Total electrical input power in watts.Output Power P_out (W)numberOptionalRequired when Use Loss Breakdown is off. Shaft mechanical output power in watts.Stator Copper Loss P_cu1 (W)numberOptionalUsed when Use Loss Breakdown is on.Iron Loss P_fe (W)numberOptionalCore (iron) loss. Used when Use Loss Breakdown is on.Rotor Copper Loss P_cu2 (W)numberOptionalUsed when Use Loss Breakdown is on.Mechanical Loss P_mech (W)numberOptionalFriction + windage. Used when Use Loss Breakdown is on.Stray Load Loss P_stray (W)numberOptionalAdditional (stray-load) losses. Used when Use Loss Breakdown is on.Decimal PlacesnumberOptional

TogglesEnable or disable optional behavior.1

Use Loss BreakdowncheckboxOptionalEnabled when checkedIf checked, P_out is derived from the loss breakdown below instead of the explicit P_out field.

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Motor Efficiency Calculator (η = P_out / P_in)

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Examples

1. Three-Phase Induction Motor Efficiency Verification

2. Motor Prototype Loss Analysis

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