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# 400V and 230V delta star connection

## 400V and 230V delta star connection

(OP)
HI there
Hope somebody will clarify me following topic.
It is basic, but I think that basic topics must be clear before proceeding in more complex topics

Let’s assume I fan with double connection, delta and star, @ 400/3/50
If I connect it @ star, but I fed it with 230/3/50, what will happen ?
I assume that since the voltage between phases, @400/3/50 and star connection is 400/(rad(3)), then 230V, the fan will have the same rotation. The voltage between phased is the same
What about absorbed current and therefore power ?
Can anybody suggest me a useful link to study this topic ?
Thanks !!

### RE: 400V and 230V delta star connection

In delta and 400 Volts applied, each winding receives 400 Volts.
In star and 400 Volts applied, each winding receives 230 Volts.
In star and 230 Volts applied, each winding receives 133 Volts instead of the normal 400 Volts.
Torque will be about 1/9 of normal.

Bill
--------------------
"Why not the best?"
Jimmy Carter

### RE: 400V and 230V delta star connection

400V-wye, 3-phase motors can be wired 230V-delta if your available power is 230V, 3-phase! Not the other wasy around.
What @waross said. The motor will be happy when supplied with the correct voltage at its windings. Wiring the motor in wye and supplying only 230V will give your motor windings just 230V/1.732 = 132.8V, which is 33.2% of the required winding voltage (400V). The motor torque will then be 11% of the rated motor torque (1/9th).

### RE: 400V and 230V delta star connection

(OP)
@waross, @ Parchie

Many thanks !
Please, would you be so kind to recommend me a link or a book where I can study and improve my knowledge on this topics
(means delta, star - or wye -, tension and torque relations)

### RE: 400V and 230V delta star connection

(OP)
@waross, @ Parchie

Just to go back to my question, and to verify if I have understood correctly
Case 230/3/50

I will connect in Delta.
I will have 230V tension between the wiring
The fan will have the same rotational speed that it would have if connected in star and 400/3/50.

Sorry for odd questions, a lot to learn.

Thanks

### RE: 400V and 230V delta star connection

Yes, your motor will behave in exactly the same way.

### RE: 400V and 230V delta star connection

It depends;
Is this a double voltage motor or a 400 Volt motor with star/delta starting?

Bill
--------------------
"Why not the best?"
Jimmy Carter

### RE: 400V and 230V delta star connection

(OP)
@waross
it is a 400V motor with star and delta wiring.

More in general, and I apologize if I am so stickler, would someone be so kind to send me a link or a book reference in order to improve my knowledge in these topics ?
It would be very nice !

Thanks

### RE: 400V and 230V delta star connection

For motors in general the Cowern Papers are a good starting place.
http://www.baldor.com/Shared/manuals/PR2525.pdf

Bill
--------------------
"Why not the best?"
Jimmy Carter

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