Voltage of 690V on the nameplate of the 15kW motor in star operation

>>17296797




On the nameplate the voltages are given for a 15kW 400 Delta /690 Star motor. Due to the power of the motor star/delta starting is advantageous. In my plant my largest motor is 45kW and has just such a start. I have my own 160kVA transformer. Medium voltage line 20kV after the transformer 3x400V. Gentlemen are professionals and you have it in your little finger. Where does the voltage of 690V on the nameplate of the motor for star operation come from? After all, the phase voltage is 230V in my house and the phase-to-phase voltage is 400V.
I realize that there is an answer in your posts but as a layman I cannot find it although I understand the patterns. If I had a 1.5 kW motor with the nameplate designation 400/690 Triangle/Star I could connect it in a three-phase domestic installation with the start described above.

uboot wrote:

.Where does the 690V voltage on the motor nameplate for star operation come from?

Well, from the fact that a single coil is designed to operate at 400V - if three such coils are connected in star, the motor requires a phase-to-phase voltage of just 690V to work properly.... And that we have 400V, so the operation of such a one looks mundane: with the windings connected in star we have a start, and after entering some revolutions, we switch the windings into delta and then there is operation.


According to the last shout of fashion - if you had read the posts with formulas with understanding, you would have arrived by yourself that 400 * √ 3 =690

If I had a 1.5 kW motor with a nameplate designation of 400/690V 50Hz Triangle/Star, could I connect it in a domestic three-phase installation with star-delta starting? If so, where does it get the 690V phase-to-phase voltage in the domestic installation?

uboot wrote:

If so, where does it get the 690V phase-to-phase voltage in a domestic installation?

I just wrote that it doesn't - it's 400V.
It's just that, during start-up, the coils get less voltage (because in star they require 690V and they get 400...) so the start-up current is less too.
Eh

Thank you for your understanding. As I wrote above I am a layman therefore my questions may cause a lot of impatience in people who deal with these issues every day.
I would also like to ask whether the 45 kW 400/690V 6-pole motor, the parameters of which I have posted above, can be operated in the star in S1 mode if the power requirement does not exceed 15 kW and whether it then corresponds to the energy consumption exactly like a motor with a maximum power of 15 kW 400/690V -6 poles?

No, it won't.
I mean it will work maybe but not optimally.
Look for the right motor and that's it.
Unless you want to play around with an inverter and gearbox - but that's an even more expensive and stupid solution....

Thanks for the clarification, Andrew. 42 - I will remember that for the rest of my life.

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