How much current is required for 1phase 230volt pumping motor?

Answer 1

There are 3 most commonly used methods of starting single-phase AC induction motors: Shaded Pole: This method is commonly used on small AC induction motors, like might be found in an ice cream freezer or electric fan. It involves a physical object acting as a small coil which causes a separate starting magnetic field out of phase with the main field generated by the primary induction coil. This causes a torque to develop across the rotor shaft upon application of AC current which starts the motor turning. Once turning, the rotor rotates concurrent to the main coil's field and no longer needs the starting force, which actually lowers motor efficiency and slows rotation when the rotor gets up to speed. For this reason, the starting force is kept low to avoid excessive motor heating through loss of efficiency. Capacitor Start: This method is commonly used on larger AC induction motors, like might be found in an air-conditioner blower motor or compressor. In a Capacitor Start motor, a second coil offset somewhat from the main coil, is connected in series with a capacitor to cause a phase shift. This provides a starting torque for the rotor stronger than the shaded-pole motor and also more efficiently, but still interferes with overall motor efficiency and causes extra heating once the rotor is up to speed. "Split-phase" or Switch Phase: This method is commonly used on motors that require a great deal of starting torque, like many washing machines and some dryers. So-called "Split-phase" motors use a more powerful offset coil and capacitor combination that is turned on and off by a centrifugal switch controlled by the rotor speed. When the motor is stopped or turning slowly, the centrifugal switch engages the start winding and provides maximum torque for starting the motor. When the rotor speed increases, the start winding is disengaged by the centrifugal switch, and this leaves the motor spinning on the main coil only. This increases motor efficiency by leaving the start winding off during the motor run time and reduces motor heating.

Answer 2

The starting current of a motors is governed by the full load amperage that the motor draws when running. Being three phase or single phase or voltages from 120 volts to 600 volts, the amperage can be from 300% to 600% of the FLA. Look for a specification sheet from the motor's manufacturer and this type of data should be included in the data.

Answer 3

It depends on the power and efficiency of the motor.