Motors
When an electric motor is first energised, the rotor is not moving, and a current equivalent to the stalled current will flow, reducing as the motor picks up speed and develops a back EMF to oppose the supply. AC induction motors behave as transformers with a shorted secondary, until the rotor begins to move, while brushed motors present essentially the winding resistance. The duration of the starting transient is less if the mechancal load on the motor is relieved until it has picked up speed.
For high power motors, the winding configuration may be switched during start-up to reduce the current drawn.
Read more about this topic: Inrush Current
Famous quotes containing the word motors:
“When General Motors has to go to the bathroom ten times a day, the whole country’s ready to let go. You heard of that market crash in ‘29? I predicted that.... I was nursing a director of General Motors. Kidney ailment, they said; nerves, I said. Then I asked myself, “What’s General Motors got to be nervous about?” “Overproduction,” I says. “Collapse.””
—John Michael Hayes (b. 1919)