| Types of Starters |
Across-The-Line Start - 10630This is usally the most simple and least costly type of motor starter. A Single contactor is used to apply full line voltage directly to the motor. This results in quick starting with full torque available from the motor. The starting current is approximately six times the Full Load Current of the motor. This higher inrush current may be a significant consideration at higher horsepowers or when used with a standby generator and automatic transfer switch. Only three leads are required to connect this controller to the motor. |
Solid State Soft Start - 10620This is a stepless form of Reduced Voltage Starting. The line voltage is applied to the motor through a solid state power component starting at 40% of rated voltage and then ramped up over a period of 4 seconds to full voltage. This allows the motor to start at a very slow speed and accelerate to full speed in a smooth, stepless ramp from start to run. When the motor is stopped, the voltage is dropped to 85% of rated voltage and then ramped down to 40% voltage over 4 seconds before totally stopping the motor. This allows a soft stop reducing mechanical stress and hydraulic water hammer effects. The starting current is about 40% of the Across-The-Line start. Only three leads are required to connect this controller to the motor. |
Autotransformer Reduced Voltage Start - 10640This is a Reduced Voltage Starting method that takes advantage of an Autotransformer to reduce the voltage being applied to the motor for starting and acceleration. The inductive nature of the autotransformer is a restriction to the current flow and lowers the power factor of the system reducing the actual KW load on the power source during start. The starting current is approximately 42% of the Across-The-Line Start and only three leads are required to connect this controller to the motor. |
Primary Resistor Reduced Voltage Start - 10650This form of Reduced Voltage Start uses a bank of resistors in series with the motor to reduce the voltage at the motor terminals. The starting current is about 70% of the Across-the-Line start. The resistors are connected in line for 2 seconds and then bypassed to allow full voltage to the motor. This method of starting is one of the lowest initial cost reduced voltage starters, but still can be used with a standard 3 lead motor. Only three leads are required to connect this controller to the motor. |
Part Winding Type Reduced Voltage Start - 10670The Part Winding type Reduced Voltage Starter uses a special two winding motor. By energizing one winding only, a little more than half the motor is used to start and accelerate the motor. After 2 seconds, the other winding is energized and both windings then act as one to provide full horsepower and torque. Starting current is about 65% of an Across-The-Line Start. This starting method requires a special motor and 6 conductors between the motor and controller. |
Wye-Delta, Closed Transition Start - 10680Wye-Delta starting is one of the lowest starting current types of reduced voltage start. The reduction does not require external transformers, resistors, or inductors. By connecting the motor in a Wye connection for starting, the starting currents are about 33% of an Across-the-Line start. After three seconds, the motor is reconnected in a Delta pattern resulting in Full torque and horsepower. During the transition from start to run, a set of resistors keeps the motor energized through the reconnection. This results in maintained magnetizing currents allowing lower second step inrush currents. A Wye-Delta motor is required for this controller which requires 6 conductors between the motor and controller. |
Wye-Delta, Open Transition Start - 10690Wye-Delta starting is one of the lowest starting current types of reduced voltage start. The reduction does not require external transformers, resistors, or inductors. By connecting the motor in a Wye connection for starting, the starting currents are about 33% of an Across-the-Line start. After three seconds, the motor is reconnected in a Delta pattern resulting in Full torque and horsepower. A Wye-Delta motor is required for this controller which requires 6 conductors between the motor and controller. |