Difference between star and delta connected motor

Star connected motors have a central connected point, called a short circuit point or star point and each winding receives phase voltages (230volts), star connected motor only run at one third of the motor rated torque and power, whereas delta connected motors have no connected point and each winding receives line voltages (415volts) and operates at full torque and power.
Delta and Star wiring
You also need to check the name of the motor, ascertain the operating voltage of the motor, some are 415v operating voltage and we can find there are 220v 3 phase operating voltage motors, Japanese standard. The input voltage to be considered, your input voltage, if it is 415v and motor operating voltage is also 415v, then you can connect either star or delta of the motor terminals. But, the motor operating voltage is 220v 3 phase, you can only connect on star if input voltage available is 415v 3 phase, but available input 220v 3 phase voltage motor operating voltage 220v 3 phase, delta connection is fine.


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6/28/2022 6:30 PM
i want to know more about electric meter
11/24/2020 12:05 AM
Well 1/3 is a bit of an understatement its 53% of the current and 33% of the voltage which if explained correctly its used with the motor starters aka contactors to not cause a power shortage and or easier on the motor which has a timer to run the Star Connected Contactor then have a timer switch the No Contacts to close to the Delta Contactor and helps with short circut protection all this is great but most VFD'S had all that in the T1 t2 T3/L1 L2 L3 terminal points with parameters you can change depending on the application.  

Lots of these webpages do a good job explaining the process but unless you have seen the application or real world Motor/Vfd's/Plc/process control its very hard to understand.

I'm an electrical engineer and master a electrician.
11/17/2020 8:48 PM
Please compare the power output and rpm for the same motor, wired as star and delta.  
11/12/2020 8:07 PM
Very interested
3/9/2020 1:21 PM
its mean star connection is not taken full load of motor
6/25/2019 4:58 PM
Why Delta connection should be 230V 3 Phase? Why can't we use 415 V for delta?
10/31/2017 1:12 PM
Why Delta connection should be 230V 3 Phase? Why can't we use 415 V for delta?
4/27/2017 8:15 AM
The motor connection type depends on the voltage of the system and how the motor is started.

If the power system voltage (line-to-line) is 380 V, then the motor needs to be connected in a star (wye) during the starting period and remain connected as a star for continuous running.

If the system voltage is 220 V, there is a choice: (1) for reduced voltage starting, the motor is connected as a star initially during the start period and then transitions to a delta connection for continuous running; or (2) for full voltage starting, the motor is connected as a delta during the starting period and remains connected as a delta for continuous running. Choice (1) requires a star-delta motor starter contactor.
4/27/2017 8:08 AM
A motor with the ratings Voltage 220 delta and 380 star, Can I connect in Star /Delta?
3/8/2017 8:53 AM
Thank sir ji
2/17/2017 12:34 AM
thanks very very much for your answers you gave me.
2/15/2017 9:51 AM
Thank you sir
1/18/2017 1:04 AM
I have a STAR voltage of 460V, but what is the DELTA voltage and how do I work out the calculation ?

Is there a formula for converting a STAR voltage to DELTA and a DELTA voltage to STAR.

Regards Rob
12/28/2016 7:14 PM
Plz tel me satar conection motar in warking delta conection..
And delta conection motar warking in satar conection.. Yes ya.no
12/28/2016 12:24 PM
I need the connection between star delta
8/31/2016 9:31 PM
Thank you i found this information very useful
Y. Pam Tok