Figure 10.13 Reduced Voltage Starters with Autotransformer
1. Soft Starter : A soft starter is a motor starting with voltage reduced by
using the electronics device to control the flowing of the electrical current and the
voltage used of motor. They would be series connected between the power supply and
motor or able to connect to delta motor to control the voltage that flow to the coil.
Solid state soft starter will slowly increase the voltage generated the rotation of the motor that slowly increase the smooth speed that able to reduce the traction
force and reduced the wear of a various devices such as chain. belt. gear and others
A soft starter of 3 phase motor as an advantage that the torque begun at the
variable, do not generate a maximum current, no maximum torque. A little electrical
voltage immediate reduced. Only one device required and the maintenance is zero
10.2.3 Automatic Control
The inverter is the electronics device that was developed to control the speed
of an automatic AC motor by controlling the frequency and the voltage of the electronics
energy distributed to the motor from sine wave energy is the frequency of square wave signal or Pulse signal. generated the inverter function and more capability than a solid state soft starter as shown in Figure 10.14.