Soft Starter

Schneider softstarter

Motors that run typical industrial applications employing conveyors, pumps, blowers, and compressors all have one common quality ,  they draw a large amount of current when they start up, perhaps six times what they draw during normal operation. This level of current can stress motor components and cause power quality issues on plant electrical systems, particularly for larger motors of 1 hp or more. That is why motors of this size frequently employ soft starting.

Motor Starting Method (1- DOL Method )

When a motor is switched on , there is a high inrush current from the mains, ( The starting current of an AC motor can vary from 3 to 8 times the nominal current). The high current drawn from the network can cause problems such as voltage drop, high transients and, in

Schneider Electric DOL

some cases, uncontrolled shutdown. High starting current also causes great mechanical stress on the motor’s rotor bars and windings, and can affect the driven equipment and the foundations. Several starting methods exist, all aiming to reduce these stresses To overcome this , There are several starting systems which differ according to the motor and load specifications. The choice is governed by electrical, mechanical and economic factors. The kind of load driven is also important in the choice of starting system.

Synchronous motor

Synchronous motor and induction motor  are the most widely used types of AC motor. Construction of a synchronous motor is similar to an alternator ( Ac Generator ) . A same synchronous machine can be used as a synchronous motor or as an alternator. Synchronous motors are available in a wide range, generally rated between 150kW to 15MW with speeds ranging from 150 to 1800 rpm.

3- Phase Induction Motor

Induction motors are the most commonly used electrical machines. They are cheaper, more rugged and easier to maintain compared to other alternatives.

Single Phase Induction Motor

Single Phase Induction Motor

• The single-phase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth.
• The single-phase motor stator has a laminated iron core with two windings arranged perpendicularly.
•  One is the main and The other is the auxiliary winding or starting winding

Motors

Motors vs Engines

• Motors convert electrical energy to mechanical energy.
• Engines convert chemical energy to mechanical energy.