polyphase motor standstill condition

[shakerbess]

can some body explain with a diagram the standstill conditions of a polyphase motor please hope some body can help this is driving me mad

 

[malcolmsanford]

Over to Tony here and his software application he knocks up a lovely drawing

 

[Knobhead]

When you say standstill do you mean locked rotor? If so current draw is usually based purely on the resistance / inductance of the rotor winding. So on start up the current drawn can be 6 to 8 times FLC.

View attachment 8196

This is the best way I can describe it. On start up resistance is the predominant element controlling the current, at run speed inductance takes over. The resistance is the same I’ve shown it smaller to represent it’s proportion of the current limiting.

Hope this helps

 

[shakerbess]

When you say standstill do you mean locked rotor? If so current draw is usually based purely on the resistance / inductance of the rotor winding. So on start up the current drawn can be 6 to 8 times FLC.

View attachment 8196

This is the best way I can describe it. On start up resistance is the predominant element controlling the current, at run speed inductance takes over. The resistance is the same I’ve shown it smaller to represent it’s proportion of the current limiting.

Hope this helps

thankyou very much tony you a star mate