Formuale and Tables

Standard F.L.C data for 4 Pole Motors
Rated Power 3 phase motor Star-Delta Single phase motor
KW HP Amp(380V) Amp(380V) Amp(230V)
0.37 0.5 1 - 3.4
0.75 1 2 - 5.8
1.5 2 3.5 - 11.2
2.2 3 5 - 16.4
4 5.5 8.5 4.9 28
5.5 7.5 11.5 6.7 37
7.5 10 15.5 9 -
15 20 30 17.4 -
22 30 44 25 -
37 50 72.5 42 -

Formulae

Ohms Law : I (A) = V (Volts) / R (Ohms)

Power(Watts) = V (Volts) / I (A)

Power(Watts) = I squared(A) x R (Ohms)

Reactive Impedance(XL) = 2pi x f l

Cable Current Ratings (Amps) Impedance Volt Drop Short Circuit
mm Ground Ducts Air Ohm/Km mV/A/m KA
1.5 23 18 18 14.46 25.10 0.14
2.5 30 24 24 8.87 15.36 0.24
4 38 31 32 5.52 9.56 0.38
6 48 39 40 3.69 6.39 0.57
10 64 52 54 2.19 3.80 0.98
16 82 67 72 1.38 2.40 1.53
25 126 101 113 0.87 1.52 2.40
35 147 120 136 0.63 1.10 3.86
50 176 144 167 0.47 0.82 4.80
70 215 175 207 0.33 0.58 6.72
95 257 210 253 0.24 0.43 9.12
120 292 239 293 0.20 0.35 11.52
150 328 369 336 0.16 0.29 14.40
185 369 303 384 0.14 0.25 17.76
240 422 348 447 0.12 0.21 23.04
300 472 397 509 0.10 0.18 28.80

These tables are to assist the electrical trade and are as such a rough guide and no responisbility will be accepted for incorrect application.