# Motor delta to wye

#### mtnelectrical

##### Senior Member
Would a 220 volts 3 phase delta motor work on a 208 v 3 ph wye system?

#### iceworm

##### Curmudgeon still using printed IEEE Color Books
Unless the motor is something strange, then, "Yes"

#### kwired

##### Electron manager
Delta and wye don't matter much for what you are asking about. A three phase motor regardless of if it is wye or delta wound only cares about seeing rated voltage and frequency (or at least same ratio of V/F say when using something like a VFD) and having 120 degree phase angle between each of the inputs.

That supply can be from conventional wye or delta connected source or something like a VFD that electronically simulates an equivalent source.

Now the fact your motor is rated 220 volts, one might want to check the rated frequency as most 60 Hz motors made for North American market are usually marked with 230 volt rating or 208-230 volt rating. Otherwise 220 and 208 are within 10% of one another and likely will be acceptable.

If it is a 50 Hz rated motor, problems you will have do not have anything to do with wye vs delta but rather the V/F design of the motor.

#### Besoeker3

##### Senior Member
If it is a 50 Hz rated motor, problems you will have do not have anything to do with wye vs delta but rather the V/F design of the motor.
The OP is in New Jersey so not likely a 50Hz motor.

#### iceworm

##### Curmudgeon still using printed IEEE Color Books
My response lacked context.

As kwired said, if this is a 50 HZ motor, then there a whole bunch of other issues besides the reduced voltage.

However, if the motor is a 60 hz and "220" was either a oldtimer speak for current 230V motors, or the motor is in fact 220V (a motor from the 1960s - or older), then:

Reducing the terminal voltage below rated voltage reduces the available torque proportional to the square of the voltage
Applying 208V to a 230V rated motor drops the available torque to .82%​
At rated current, the motor available horsepower is .............................................. (drum roll) ....... .82% nameplate.​

This shows up as a problem if the motor is heavily loaded. To get the motor to operate at nameplate power, requires the current to increase - 18% above nameplate. Which, of course, causes the motor to run hotter.

The typical application where I have seen this matter is in small motor (1/2 to 3 hp) HVAC. The MFGs tend to use the thinnest, 1.0sf, 208/230V motors available and load them right up to 100%. Amazingly the motors run hot and fail within a few years.

The solution is to replace with a 200V rated motor, 1.15sf if available. They run significantly cooler, last for ever (well, 40,000 hours anyway)

So, if the motor is not heavily loaded, (and 60HZ of course), or you don't mind the short life of a heavily loaded motor, then:
Yes if will work fine.

#### synchro

##### Senior Member
A 50 Hz motor would run at reduced current with a 60 Hz supply because its windings have the higher inductance that's needed at 50 Hz to prevent saturation. Therefore the torque output is reduced by a factor of ~ 5/6 from this effect. This is in addition to the reduction in torque if the motor is run at a lower voltage than the nameplate value. Obviously it would also run at about a 20% higher RPM at 60 Hz than at 50 Hz.

#### kwired

##### Electron manager
The OP is in New Jersey so not likely a 50Hz motor.
They never import anything there?

Buying a 50 Hz motor may be harder to do without special ordering, but a motor already part of some equipment might be more likely, especially if buying used equipment. New equipment hopefully someone was smart enough to order what was needed for where it will be installed.

#### Besoeker3

##### Senior Member
They never import anything there?

Buying a 50 Hz motor may be harder to do without special ordering, but a motor already part of some equipment might be more likely, especially if buying used equipment. New equipment hopefully someone was smart enough to order what was needed for where it will be installed.
I'm sure they can. I was commenting on the probability rather that the possibility.

#### mtnelectrical

##### Senior Member
Sorry , I was out the forum for a few days. The motor is part of an European Machine, Turkish to be exact. the motor is rated for 380 volts 3 phase wye and 220 volts delta and for 50Hz. I believe the best option is to get a transformer. This customer keeps bringing equipment from Turkey, So I would look into getting a big transformer for future installations

#### kwired

##### Electron manager
Do you intend to somehow convert the supply to 50 Hz? It will run faster than designed if supplied with 60 Hz. V/F ratio if run at 480V 60 Hz is about same but will at least need to use mechanical reduction (gear/pulleys) to get same speed on the driven load.

#### Besoeker3

##### Senior Member
Do you intend to somehow convert the supply to 50 Hz? It will run faster than designed if supplied with 60 Hz. V/F ratio if run at 480V 60 Hz is about same but will at least need to use mechanical reduction (gear/pulleys) to get same speed on the driven load.
I don't know what the motor ratings are but, if not very big, it might be simpler and cheaper just to swap the motors for 60Hz rated units.

#### drcampbell

##### Senior Member
... 480V 60Hz is about same ...
If you opt for 480 volts, make sure every component is good for it, not just the motor.
You don't want a flashover in the control cabinet because, for example, the socket the phase-loss-protection relay is plugged into has a dielectric strength of only 300 volts.

#### kwired

##### Electron manager
If you opt for 480 volts, make sure every component is good for it, not just the motor.
You don't want a flashover in the control cabinet because, for example, the socket the phase-loss-protection relay is plugged into has a dielectric strength of only 300 volts.
Absolutely. Control transformers might be fine also, but connected controls will still be at a higher voltage than originally intended as well.

#### iceworm

##### Curmudgeon still using printed IEEE Color Books
Do you intend to somehow convert the supply to 50 Hz? ...
I don't know what the motor ratings are but, if not very big, it might be simpler and cheaper just to swap the motors for 60Hz rated units.
Following kw and bes posts:
Maybe a vfd is cost effective.