I NEED A DESCRIPTION OF VARIOUS TYPES AND CONSTRUCTION OF INDUCTION
MOTORS AND VARIOUS METHODS FOR STARTING THEM AND METHODS OF SPEED
CONTROL?

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Request for Question Clarification by shivreddy-ga on 08 Jan 2003 11:14 PST

Hi,

I would be glad to take up this question for you. However for the
information you seek ( of which I can find no proper basic study
material on the net) this question is priced a bit low. I will have to
type out in detail the entire material which is quite vast and
exhaustive. I have books which explain Induction Motors completely
along with all features and methods you seek. I can provide you with
the names of these books if you will accept that as an answer. If you
want me to type out the basic material (as in a brief course) I can do
that too. Please let me know what you decide.

Warmest Regards,
Shiv Reddy

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Request for Question Clarification by shivreddy-ga on 11 Jan 2003 23:35 PST

Hi, 
 
I would be glad to take up this question for you. However for the
information you seek ( of which I can find no proper basic study
material on the net) this question is priced a bit low. I will have to
type out in detail the entire material which is quite vast and
exhaustive. I have books which explain Induction Motors completely
along with all features and methods you seek. I can provide you with
the names of these books if you will accept that as an answer. If you
want me to type out the basic material (as in a brief course) I can do
that too. Please let me know what you decide.
 
Warmest Regards, 
Shiv Reddy

Most small and medium size induction motors (up to about 2 HP = 1492
watts) are single phase. Bigger ones are often 3 phase. Other numbers
of phase are possible but rare. I believe sychronous moters are
basically indiction motors. Most other types run about 10% below
sychronous speed at full load. The speed can be adjusted plus or minus
about 3% on these types, but wide range speed control (with induction
motors) was impractical before heavy duty solid state components
became available. The technique is to convert the powerline ac to dc
then run a variable frequency inverter to produce the desired speed.
Other types of motors that are not induction motors are often
preferable for applications requiring a wide range of speed control.
Induction motors for washing machines are sometimes 2 pole for spin
and 4 or 6 pole for other functions such as wash. More poles allows
1/2 or 1/3 speed.
 Generally the stationary winding of an induction motor is similar in
design and funtion to the primary of a tranformer. The rotating part
is a very low voltage transformer secondary.
 The shaded pole induction motor runs on single phase at sychronous
speed for clocks and precice timing functions, phonograph moters and
perhaps hard drives, CD players and DVD. They are rarely built over
1/10 th HP as they have low effeciency.   Neil