On Sun, 08 Jan 2006 00:23:18 +0000, wrote:



A squirrel cage motor DOES generate a back EMF and will continue
to do so for several revolutions after all power has been removed
even if it has zero permanent magnetism.

In the case of a 2 pole motor, at the instant of disconection,
the induced circulating currents in the short circuited rotor
inductance provide a diametrical NS field which decays at at the
rotor L/R rate for several tenths of a second. The voltage
generated by this decaying field is is easily observed with an
oscilloscope - the initial voltage is close to full supply
voltage.

Jim

I stand corrected. It makes sense, now that you point it out. L/R
ratio is pretty high because R is quite small.

Thanks, Jim!