Soft Starters Reduce Operating Costs, Improve Efficiency

Toledo, OH - Gasoline and diesel-powered generators are used by many plants, including recycling, to produce electric power for AC induction motors, used with portable machinery, as well as for emergency backup in the event of a power failure in the plant.

To insure long-term operation, a generator must be capable of producing power that exceeds the highest requirements for inrush current necessary to accelerate the motor and connected equipment to normal operating speed.

A magnetic motor starter (aka Across-The-Line starter) will accelerate a motor and its connected equipment very rapidly over a short time period. The resulting power produced by the motor requires a significant inrush of current to the motor (typically six to eight times motor rated full load current).

The effect of such high inrush current demand impacts the selection of a suitable generator. For example, a portable scrap shredder equipped with a 350 HP, 460/3/60, 400 Amp motor started "Across-The-Line" will require a generator capable of supplying demand current ranging from 2,400 to 3,200 Amps.

An electronic soft starter, with advanced technology, produces smooth acceleration over a set time period. Very advanced models use a controlled torque speed ramp to provide starting inrush current ranging from 2.3 to 3 times motor rated full load current, lower than traditional reduced voltage starters.

A soft starter with torque speed ramp used to start the before mentioned shredder will require a much smaller generator, capable of supplying a demand current range of 920 to 1,200 Amps.

Soft starting provides additional benefits for the customer, including: motor life that is extended by reducing motor overheating during starting and reducing the impact of high starting torque on motors, drive couplings, belts and equipment. These dramatically lower maintenance costs and improve process efficiency.