The same method applies in carrying out the procedure for determining the internal winding configuration of the 9 leads delta connected motor similar to the procedure applied to the 9 leads star connected motor, which is to make use of an ohm meter to measure the continuity of the motor's internal coil winding through the wiring terminals accessible from the motor's terminal box. Before measuring the continuity of the motor's internal connection, make sure that all external wiring terminal of the motor is disconnected first to ensure accurate continuity readings.
For a factory pre-configured 9 leads delta connected motor, there is a continuity reading through terminals 1-4-9 and also through terminals 2-5-7 and 3-6-8 (see drawing provided below for details). Obtaining these continuity readings confirms that the motor is internally configured for a delta connection.
Similar to the 9 leads star connected motor, 9 leads delta connected motors are also made available with operational capability for both high and low voltages. The dual operational voltage rating values of the motor is determined from the motor's nameplate. A most commonly used example is a 9 leads motor intended for 220 and 440 volts operation. Each of these designated voltages requires different methodology of wiring connection in order to run the motor in either 220 or 440 volts operation.
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Fig-1: 9 Leads 3 Phase High Volts Delta Connected Motor Configuration
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To connect the motor to its rated high voltage configuration, Fig-1 above shows an electrical schematic diagram of a delta configured 9 leads motor so connected for a 440 volts AC power supply. The 3 phase AC source line voltage L1 is connected to the motor terminal 1, line voltage L2 to motor terminal 2 and line voltage L3 to motor terminal 3, while also individually joining together motor terminals 4-7, 5-8 and 6-9 respectively (refer to above drawing).
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Fig-2: 9 Leads 3 Phase Low Volts Delta Connected Motor Configuration
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To connect the motor to its rated low voltage configuration, Fig-2 above shows an electrical schematic diagram of a delta configured 9 leads motor so connected for a 220 volts AC power supply. The 3 phase AC source line voltage L1 is connected to the motor terminal 1-6-7, line voltage L2 to motor terminal 2-4-8, and line voltage L3 to motor terminal 3-5-9 (refer to above drawing).
Another variation of wiring configuration for a 9 leads motor connection apart from the 9 leads delta connection is the 9 leads star (wye) wiring configuration.