18 April 2021

Advantages and disadvantages of auto transformer starter

An autotransformer is a laminated core transformer with just one winding. It is similar to a two-winding transformer but differs in the way the primary and secondary windings are interconnected, with a portion of the winding shared by both primary and secondary sides. So here this article gives the information about the advantages and disadvantages of autotransformer stater to better understand this topic. 

Advantages of autotransformer starter:

  • The autotransformer's most powerful ratio is between 65 and 80 percent.
  • The torque per ampere of supply current is maximum.
  • The current in the motor is greater than the current in the supply.
  • It is less expensive.
  • This approach works well for long start-up times.
  • Starting voltage can be adjusted by selecting the appropriate tap on the autotransformer.
  • The circuit benefits over starting with a regular autotransformer, which needs to be at some point completely disconnected during the start inducing high voltage impulses, which can damage the electrical insulation of the stator.
  • The inrush current is greatly reduced by the autotransformer starter.
  • It is used for large motors that cannot be started by connecting directly to the network. The star delta stater cannot be used for large motors, particularly if they are started with a significant load.
  • improved regulation
  • The inrush current is greatly reduced by the autotransformer starter.

Disadvantages of autotransformer starter:

  • The circuit is complex and involves a relatively expensive autotransformer
  • Due to the size of the autotransformer starter, a much larger control, the panel is required which increases the price.
  • If space is limited, it might not be possible to connect the korndorfer starter to an existing machine due to its physical size.
  • One of its major drawbacks is the frequency constraint of its operation. It is always necessary to know the operation frequency in order to select an autotransformer that is appropriately rated.
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