The previous article presented the terminal wiring connection for a 12 leads star (wye) configured induction motor. Another type of 12 leads wiring configuration which is a distinguished counterpart to the star (wye) motor connection is the delta configuration. Again this type of connection will also have 12 wiring terminals directly accessible from the motor's terminal box which serves for external wiring purpose.
Similar to the 12 leads star (wye) configuration, the 12 leads delta configuration is also made available for dual voltage application. It is designed to operate with a selection of wiring configuration for a variation of source voltage ratings for both high and low voltage operation.
The rated operational voltage designed for the motor is determined from the motor's nameplate. Whenever in doubt, a detailed wiring information for each designated voltages designed for the motor's operation is also provided on the nameplate, or alternatively, wiring configuration for specific voltage operation can also be found 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 voltage operation. The electrical drawings shown below illustrates a standard 12 leads wiring connection for induction motors rated with dual voltage functionality in delta configuration.
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| Fig-1: 12 Leads 3 Phase High Volts Delta Connected Wiring Configuration |
To connect the motor to its rated high voltage configuration, Fig-1 above shows an electrical schematic diagram of a delta configured 12 leads motor so connected for a 440 volts AC power supply. The 3 phase AC source line voltage L1 is connected to the motor terminals 1-12, line voltage L2 is connected to the motor terminals 2-10 and finally line voltage L3 is connected to the motor terminals 3-11, while also individually joining together motor terminals 4-7 then 5-8 and finally 6-9 respectively (refer to above drawing).
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| Fig-2: 12 Leads 3 Phase Low Volts Delta Connected Wiring Configuration |
To connect the motor to its rated low voltage configuration, Fig-2 above shows an electrical schematic diagram of a delta configured 12 leads motor so connected for a 220 volts AC power supply. The 3 phase AC source line voltage L1 is connected to the motor terminals 1-6-7-12, line voltage L2 is connected to the motor terminals 2-4-8-10 and finally line voltage L3 is connected to the motor terminals 3-5-9-11 (refer to above drawing).
Another variation of wiring configuration for a 12 leads motor connection apart from the 12 leads delta connection is the
12 leads star (wye) configuration.
