A common two pole squerrel cage induction motor slips down about 4% from
line frequency of 3600 rpm to about 3450 rpm. So lets just look at it as a
movie film going in reverse. The prime mover speed would have to be around
3750 X 96% to yield 60 cycle.
If you want 30 cycle. Then thats half as much.
Here is a little trick I once figured out that is much easyer than the
formulas that they give you. Since almost all of the AC motors I worked on
were 60 cycle per second I just devide the number of poles in the motor
into 7200 to get the synchronous speed. Then if it's an induction motor
you must figure the slip.
NOTE, The more poles, the more slip.
One last thing. If the Induction motor don't work as an Alternator the
first time
then connect the motor leads to a 12 volt automobile battery for one half
of a second. This will induse a residual magnitism into the rotor. Once
generating, it will build on itself.
Hope this helps.
Sincerely, Boyd
-------------------------------------------------------------
To leave this list, email <listserver@keelynet.com>
with the body text: leave Interact
list archives and on line subscription forms are at
http://keelynet.com/interact/
-------------------------------------------------------------