Tag Archives: no load test

No-load test induction motor

The test is performed at poly-phase voltages and rated frequency applied to the stator terminals. When motor runs for some times and bearings get lubricated fully, at that time readings of applied voltage, input current and input power are taken. To calculate the rotational loss, subtract the stator I2R losses from the input power.

theory of no load test of induction motor

Calculation of No Load Test of Induction Motor

Let the total input power supplied to induction motor be W0 watts.

Where,
V1 = line voltage
I0 = No load input current

Rotational loss = W0 – S1
Where,
S1 = stator winding loss = Nph I2 R1
Nph = Number phase
The various losses like windage loss, core loss, and rotational loss are fixed losses which can be calculated by

Stator winding loss = 3Io2R1
Where,
I0 = No load input current
R1 = Resistance of the motor

Core loss = 3GoV2