Question

A 0.5 hp, 6-pole induction motor is excited by a 3 –phase, 60 Hz source. If the full-load speed is

1140 rpm, calculate the slip

Answer 1

We know that,

$Ns=120*\frac{f}{(P)}$

$=120*\frac{60}{(6)}=1200$

$slip=\frac{(Ns-Nr)}{(Ns)}$

$=\frac{(1200-1140)}{(1200)}$

$=0.05$