Rumus Dasar untuk perhitungan motor induksi
Kecepatan Sinkron
Synchronous motor speed (NS ) = 120 x frekuensi / poles
………………………………………….= 120 x f / p
………………………………………….= rpm
Persentase Motor Slip
Persen Motor Slip (%S) = ((NS – NR) / NS ) x 100
Kecepatan Rotor
Rotor Speed (NR) = NS x (1 – %Slip)
Torsi (Torque)
Output Motor Torque, ft.lbs. (T) = hp x 5252 / rpm
Power
Power Input (Pin ) = S3 x V I Cos Q
Power Input (Po ) = Pin – Machine Loss
Efisiensi
Efisiensi = Po/Pin
………….= (Pin – Machine Loss) / Pin
Power Factor
Percent Power Factor (Cos Q) = Pin / kVA
…………………………………………= (kw / kVA) x 100
Arus suplay
Line Current, amps (IL) = (hp x 746) / (V x Eff x Cos Q x S3)
Kerapatan Gap
Air Gap Density = Flux / Area
……………………..= Bg µ V / f
Torsi (T) µ Bg2 µ hp
Slip µ 1/Bg2 µ 1/V2
Keterangan = µ : Sebanding