effect of speed changing on electric motors 1

[Abdzaidy]

Hello every one
Can you please explain what is the effect of speed changing on electric motors ?

 

[jraef]

They spin slower?

What do you mean by "effect"?


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[davidbeach]

No, not slow down, come on they go faster. ;-)

 

[crshears]

Abdzaidy, please clarify your question; absent any other details, there is a hugely finite number of ways of answering you...

Are you asking about the effect of changing the speed of an electric motor by altering [ presumably increasing ] its applied load?

If so, what kind of motor?

Or are you asking about varying the speed of an AC induction motor using a VFD?

Or are you asking about varying the speed of a DC motor by altering the applied voltage?

Or something else?

 

[Abdzaidy]

Dear crshears,
Thank you in advance... yes my question was about the effect of changing the speed of an electric motor by altering [ presumably increasing ] its applied load?

 

[krisys]

It is dictated by the motor manufacturer's published torque-speed, current characteristics.

 

[waross]

Many motors slow down with increasing load.
Some do not, such as synchronous motors.
All run hotter at higher loads.
How much do they slow down? that depends.
From the Cowern Papers

From this you can see the effect of torque loading on the speed of 4 types of squirrel cage induction motors.
When the torque load is greater than the breakdown torque, the motor stalls.
When the torque demanded by the load falls as the speed drops, it depends.

Bill
--------------------
"Why not the best?"
Jimmy Carter