Motor Slip
Consider a 4 pole induction motor with a line voltage frequency of 120 Hz. If the motor shaft spins at 2,000 rpm, what is its slip?
Expand Hint
The slip for an induction motor is:
$$$slip=\frac{(n_s-n)}{n_s}$$$
where
$$n$$
is the rotational speed.
Hint 2
The synchronous speed for ac motors is:
$$$n_s=120*f/p$$$
where
$$f$$
is the line voltage frequency in Hz, and
$$p$$
is the number of poles.
The synchronous speed for ac motors is:
$$$n_s=120*f/p$$$
where
$$f$$
is the line voltage frequency in Hz, and
$$p$$
is the number of poles.
For a 4 pole motor operating on 120 Hz voltage:
$$$n_s=120*120/4=3,600\:rpm$$$
The slip for an induction motor is:
$$$slip=\frac{(n_s-n)}{n_s}$$$
where
$$n$$
is the rotational speed.
$$$slip=\frac{(3,600rpm-2,000rpm)}{3,600rpm}=\frac{1,600}{3,600}=0.44$$$
0.44
Time Analysis
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