Motor with Y/YY configuration

[tahir4awan]

Hello,
normally we deal with motors with delta and star configuration now we have a pole changing motor with Y/YY confuguration. This motor has 9 Terminals. According to manual the motor can be connected in low or hight voltage. If you see the name plate. 460 or 400V is for Y and 230 or 208V is for YY.

The confusing part is, why we connect YY in 230V. I have searched internet but could not find any formula, so we calculate the phase voltage for YY.

I have looked in electrical books, but strangely YY is always connected to 400V.

Does anyone have any idea, what is the standard phase volatge of YY when Y has 400V?

Thanks

 

[KlausST]

Hi,

I´ve not much experience with motors ... so I´m not very sure...

To me "pole changing" motor always referred to RPM changing. This is obviously not the case here.
I can only guess:
* There is "YY" made for RPM changing (always 400v)
* there is "YY" made for voltage adjust (not always 400v) (your case)
(the difference is how the windings are mechanically (angle) distributed in the motor)

So for me it is just a motor made for two different voltages. Maybe for international use, when different countries have different grid voltages.

YY for me means that there are two pairs of windings each in star connection.
so you may connect them in parallel "YY" or you may connect the individual legs of the star in series to get a "big Y" .. for twice the individual voltage.

--> I recommend to follow the wiring informations provided by the motor manufacturer. In case of problems: contatct them.

Klaus

 

[FvM]

To clarify the question, can you show the connection schemes for said 208/230/400/460 V operation. I presume they are all different.

Or is 208/230 and 400/460 V the same circuit, as in below diagram?