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Triphase motor connection

Triphase motor connection

Triphase motor connection

(OP)
Hey there,

I'm from Spain, so the threephasic system we have here is 230-400V and 400-690V for industrial purposes.

If I have a Δ230-Y400 motor and I want to connect it to the 230-400V, I suppose that the only way is in star connection. As far as I know, the coils are prepared for 230V between their terminals so, as the line tension is 400V, I will burn the motor if I connect in triangle.

The same happens with the 400-690V system with a Δ400-Y690 motor.

The two final posibilities is to connect a Δ230-Y400 motor to a 400-690V system (the motor will burn anyway) and to connect a Δ400-Y690 motor to a 230-400V (in star it will run slower, and in triangle it will go OK).

I think I'm doing something wrong with all of this... Can anyone help me??

RE: Triphase motor connection

The connections are pretty clear for each voltage.

What exactly is your doubt or question?

Muthu
www.edison.co.in

RE: Triphase motor connection

(OP)
Hi edison123,

If I have a Δ230-Y400, does this mean that the coils are thermal protected for 230V?? Is that right??

Then, if I connect this motor to a 230-400V electric gird in triangle, I will burn the motor!! Each coil is receiving 400V!!

RE: Triphase motor connection

It depends on what your main grid voltages is, ​between the phases.
In Sweden and most of Europe it is 400 VAC.
For Norway not so, in Spain?
And what exactly is written on the motor plate.

Quote:

Connection of 3-phase single-speed motors

3-phase single-speed motors can be connected in two ways; "D" and "Y".

Voltage across the motor winding
For D-connected motor: Equal to mains mains voltage
For Y-connected motor: 1 / √3 × mains mains voltage

Connection to mains with main voltage 400V:
Motors marked "400 / 690V" or only "400V": D-connected, can be Y / D-started if necessary
Motors marked "230 / 400V" or only "230V": Y-switched, can not be Y / D-started

Connection in mains with main voltage 230V:
Motors marked "230 / 400V" or only "230V": D-connected, can be started Y / D if necessary
Motors marked "400 / 690V" or only "400V": Can not be used

The stator sockets are marked according to Swedish and international standards U, V, W.
Clockwise direction of rotation seen
The D-side (drive end) is available if the phase sequence of the mains is 1, 2 and 3 and the phases are connected to the motor stator terminal (terminal block)ng phases are switched.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Triphase motor connection

Dear Mr. Kalabagh (Mechanical)
"...I'm from Spain, so the threephasic system we have here is 230-400V and 400-690V for industrial purposes.
If I have a Δ230-Y400 motor and I want to connect it to the 230-400V,... is in star connection. ... with the 400-690V system with a Δ400-Y690 motor. The two final posibilities is to connect a Δ230-Y400 motor to a 400-690V system (the motor will burn anyway) and to connect a Δ400-Y690 motor to a 230-400V (in star it will run slower, and in triangle it will go OK)...."

1. The standard EU LV is 230-400V (50Hz). In Spain ? It is unlikely? that you have 400-690V from the utilities, but you may have it in your own installation. It should be understood that 230-400V means that any Line to the Neutral is 230V and any Line to Line is 400V. A 400-690V system with any Line to the Neutral is 400V and any Line to Line is 690V.
2. A D230-Y400 motor is suitable for connection to a 230-400V system with motor winding in[ Y ] formation. Not suitable for SD starting. For SD starting, the motor shall be D400-Y690.
3. A D400-Y690 motor is suitable for connection to a 230-400V system with motor winding in [ D ] formation. This motor is also suitable for connection on to 400-690V system with winding in [Y ] formation.
4. A D400-Y690 motor with winding in [Y ] formation when connected on to a 400-690V system would retain its rated kW power and speed ratings. It would run at a lower current (therefore smaller conductor).
Che Kuan Yau (Singapore)

RE: Triphase motor connection

I agree with zlatkodo.
There is no way you can connect a 230-400V motor in 400-690V system.

RE: Triphase motor connection

@kalabagh

230 V Low voltage = Delta (triangle as you call it).

400 V High voltage = Wye (or star)

In both cases, the phase voltage remains the same at 230 V.

Same logic for 400/690 V connections.

Muthu
www.edison.co.in

RE: Triphase motor connection

(OP)
Hi che12345,

1. The standard EU LV is 230-400V (50Hz). In Spain ? It is unlikely? that you have 400-690V from the utilities, but you may have it in your own installation. It should be understood that 230-400V means that any Line to the Neutral is 230V and any Line to Line is 400V. A 400-690V system with any Line to the Neutral is 400V and any Line to Line is 690V.
2. A D230-Y400 motor is suitable for connection to a 230-400V system with motor winding in[ Y ] formation. Not suitable for SD starting. What would happen if I connect it in D?? For SD starting, the motor shall be D400-Y690.
3. A D400-Y690 motor is suitable for connection to a 230-400V system with motor winding in [ D ] formation. And why not in Y formation?? This motor is also suitable for connection on to 400-690V system with winding in [Y ] formation. What would happen if I connect it in D??
4. A D400-Y690 motor with winding in [Y ] formation when connected on to a 400-690V system would retain its rated kW power and speed ratings. It would run at a lower current (therefore smaller conductor).

RE: Triphase motor connection

Not sure I understand your problem so I will try it like this.

Quote (Kalabagh)

I'm from Spain, so the three phasic system we have here is 230-400V and 400-690V for industrial purposes.

If I have a Δ230-Y400 motor and I want to connect it to the 230-400V, I suppose that the only way is in star connection.
Yes in Y (star). Then you will have 230 VAC over each coil since the "centrum point" is 0 (Neutral)

Quote (Kalabagh)

As far as I know, the coils are prepared for 230V between their terminals so, as the line tension is 400V, I will burn the motor if I connect in triangle.
Yes it will burn in D. The current will be √3 = 1,73 higher if you connect it in D (triangle) since the voltage over the coils will be 400 instead of 230 VAC

Quote (Kalabagh)

The same happens with the 400-690V system with a Δ400-Y690 motor.
Yes

Quote:

The two final posibilities is to connect a Δ230-Y400 motor to a 400-690V system (the motor will burn anyway)
Yes, can't be done then you would have 400V AC over the coils and it is made for 230 VAC and the current will be √3 = 1,73 higher

Quote:

and to connect a Δ400-Y690 motor to a 230-400V (in star it will run slower, and in triangle it will go OK).
Yes in Y it will have less start current and torque.
Then you will have 230 VAC over the coils which they can take because the current is 1/1,73 = 0,58% less.
But when it has picked up speed you change it to D (tringle) and then it runs as usual and you will have 400 V AC over the coils.

Quote:

I think I'm doing something wrong with all of this...

Not sure you are actually. winky smile

Unless there is something else that's bothering you?

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Triphase motor connection

Quote:

Yes it will burn in D. The current will be √3 = 1,73 higher if you connect it in D (triangle) since the voltage over the coils will be 400 instead of 230 VAC
At 173% overvoltage, the motor may be expected to saturate magnetically and the current will be much higher than 173%.
It will burn faster than simple arithmetic suggests.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Triphase motor connection

(OP)
Hi RedSnake,

This is a good answer for me.

Then, what about VFD drives. In a drive you can enter both the tension and the current. Does this mean that, generally, you can supply different values of tension and different values of current as you want??

I know that opening the issue of drives is a big deal but my question is simple

Thanks

RE: Triphase motor connection

A VFD regulates the speed.
You can limit the torque but you can't apply it.
You can not take out more torque then the motor can deliver.
And the drive need to be able to deliver the amount of power that is needed for the the motor work at its max torque.
Motors for VFD drives has different speeds and torque curves classified in S1 to S8 (Duty cycle) depending on how much internal heat they can withstand (the power consumption and the interwall or continuity).
So you need to know how much torque and max speed you will need from the motor and how often, to choose a motor.
Then you need to choose a drive that can deliver what is needed.
Most motor and VFD manufactures will be able to help you with this.

(A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Triphase motor connection

Dear Mr. Kalabagh (Mechanical)
1. " ....2. A D230-Y400 motor is suitable for connection to a 230-400V system with motor winding in[ Y ] formation. Not suitable for SD starting. What would happen if I connect it in D??...."
The motor winding is rated for 230V. When winding connection is in D, but connect it on to a 400V mains; the winding is [over-voltage]. Permanent damage will happen.
2. " ....3. A D400-Y690 motor is suitable for connection to a 230-400V system with motor winding in [ D ] formation. And why not in Y formation?? This motor is also suitable for connection on to 400-690V system with winding in [Y ] formation. What would happen if I connect it in D??..." A D400 winding motor the winding is rated 400V..."
2.1 When connected in Y, it is rated for 690V. When connect to a 230-400V mains, the winding is [under-voltage]. Permanent damage will happen.
2.2 When connected in D , it is rated for 400V. When connected to a 400-690V mains, the winding is [over-voltage]. Permanent damage will happen.
Che Kuan Yau (Singapore)

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