All 12 leads motors are most commonly made for dual voltage application. This means that the motor was specifically designed for dual voltage operation which can be supplied with either low voltage or high voltage configuration. The motor will have to be appropriately selected accordingly, which is basically dependent on the application for which the motor is intended to operate based on the available source voltage where the motor is to be installed.
For the purpose of providing an example, the most common operational voltage for induction motors in most industrial application are motors designed to operate with 220 and 440 volts power supply. The rated operational voltage of any induction motors can be found from the motor's nameplate. It is also a standard practice for motor manufacturers to provide information about the motor's specific wiring connection for both low and high voltages on the motor's nameplate or on the cover of the motor's terminal box.
Each of the rated voltage values intended for the motor's operation requires different methodology of wiring connection in order to run the motor in either low or high volts operation. The electrical drawings shown below illustrates a standard 12 leads wiring connection for induction motors rated with dual voltage functionality in star (wye) configuration.
|Fig-1: 12 Leads 3 Phase High Volts Star (Wye) Connected Motor Configuration|
|Fig-2: 12 Leads 3 Phase Low Volts Star (Wye) Connected Motor Configuration|
Another variation of wiring configuration for a 12 leads motor connection apart from the 12 leads star (wye) connection is the 12 leads delta wiring configuration.