how to limit the current inflow in motor

These are called "soft start" controllers and are an off the shelf item.

Basically a ramped triac.

There are a couple of ways you can go. First you can turn the motor off if you know you won't need it for a while. This is by far the simplest solution if you can predict when the motor is needed.

Assuming this is an induction motor:

If you need to be able to react quickly and can't wait for the motor to spin up, you will need a more complex solution. There are devices that decrease the voltage applied to the motor when the motor is lightly loaded. These devices monitor the phase angle of the current into the motor. On a lightly loaded motor the current lags the voltage by nearly 90 degrees. This current causes I^2R losses. Lowering the voltage, reduces the current and thus reduces the losses.

These devices have to be carefully designed. A less than careful design could allow a DC component to flow through the motor. This is very bad because it increases the losses in the motor to perhaps more than the full load losses.

These controllers have a nice side feature. They make the motors speed depend less on the load on the motor. When the voltage on the motor is reduced, it slows down very slightly.

hi hami,

u have certain question regarding motors and clutch. actually my sandy, equipment maintenance engg., CDIL when we use clutch, i think it will not effect on the amperes of the motor. it is just a mechanism for transmitting rotation, which can be engaged and disengaged. the clutch connects the two shafts so that they can either be locked together and spin at the same speed.

if u dont want to engaged clutch and require ideal running and also reduce consumption during ideal running, then u have to use AC drive or VFD(variable frequency drives). A variable frequency drive is an adjustable speed drive. Adjustable speed drives include all types; mechanical and electrical

hami, i am also new in this field. if i am wrong then pls feel free to tell me where i m wrong

reply

ok byeee sandy