I have a BLDC 3 phase 8 pole motor, with hall effect sensors, most other three phases motors have 1 wire for each phase U , V , W however this motor has two for each phase(these do not include the separate hall effect sensors, of which there are 5 as expected). Does any one know the reason for this, I have attached the motor specification sheet.

Best Regards


  • 1
    \$\begingroup\$ This way it's easy to connect them to isolated inputs: completely separate plus and minus. Personally i like it very much. Although you definitely have a datasheet of something else. \$\endgroup\$ – Gregory Kornblum Feb 12 '16 at 18:16
  • \$\begingroup\$ Thank you for your response, however your reply is very vague, and I am unsure what you mean about the datasheet this was provided by the manufacturer with the motor. why would you need isolated inputs plus/minus for each phase??? \$\endgroup\$ – James Weston Feb 12 '16 at 18:25
  • \$\begingroup\$ You know, it happens sometimes :) either the motor is not what is described in DS, or you didn't describe correctly the situation. \$\endgroup\$ – Gregory Kornblum Feb 12 '16 at 18:28
  • \$\begingroup\$ As the datasheet suggests, it allows you to connect them as either star or delta, depending on which your application requires. \$\endgroup\$ – Tom Carpenter Feb 12 '16 at 18:37
  • \$\begingroup\$ Well its most likely I have not described the situation correctly, as this is definitely the data sheet which describes the motor. I am a mechanical engineering student, therefore my electronics knowledge is more limited its possible there is something simple I am missing. \$\endgroup\$ – James Weston Feb 12 '16 at 18:41

If you have a 3-phase \$\Delta\$ connected BLDC, you would expect three wires - one for each joined pair of phases (e.g. one for \$U_1 V_2\$, one for \$V_1 W_2\$ and the third for \$W_1 U_2\$).

If you have a 3-phase Y connected BLDC, you would expect again three - one for each phase (e.g. one for \$U_1\$, one for \$V_1\$ and the third for \$W_1\$, where \$U_2\$, \$V_2\$, and \$W_2\$ are connected internally).

In your case you have six wires. This means there are no internal connections. You are presented with all of \$U_1\$, \$V_1\$, \$W_1\$, \$U_2\$, \$V_2\$, and \$W_2\$ individually. This means you get the option of what topology you want. You make the connections to form either a Y or \$\Delta\$ externally.

Now, if we assume that the solid colour cables are the first side of the coil (e.g. \$U_1\$), and the striped cables are the second side of each coil (e.g. \$U_2\$), then you should be able to work out the connections based on my description above.

For Y simply connect all of the striped cables together, and each of the solid cables go to your motor driver.

For \$\Delta\$ connection, connect the cables in sequence so that each port of your motor driver is connected to both a striped and a solid colour cable (though not the same colour!). For example you could connect Yellow with Red Stripe, Red with Black stripe, and Black with Yellow stripe.


yes. I agree whit above answer. the motor manufacturer provide you to use the motor as stare or delta. it depend on your deriver strategy to witch one of them.


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