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Run Wye motors on Delta system?

Run Wye motors on Delta system?

Run Wye motors on Delta system?

(OP)
We have specified Wye motors but customer now tells us he has ungrounded delta system.  Is this a problem? If so, what are our options?

RE: Run Wye motors on Delta system?

No problem.

RE: Run Wye motors on Delta system?

The internal motor connection pattern has no direct relation to the power system configuration pattern. All that matters is voltage.

Eng-Tips: Help for your job, not for your homework  Read FAQ731-376

RE: Run Wye motors on Delta system?

Hello PappaFuzzy

The only times that you need to be concerned about Wye or Delta connections if if you are going to run a four wire connection to the motor (don't understand why) or if you are going to use a star/Delta (Wye/Delta) starter, or you are going to use a soft starter in six wire (inside delta) connection. For standard three wire winnections between the starter and the motor, there is no difference provided that the motor is connected in the correct configuration for the applied voltage.

Best regards,

Mark Empson
http://www.lmphotonics.com

RE: Run Wye motors on Delta system?

davidbeach said it all.
jraef said the same thing in different words.
There are some issues called "discontinous ground faults' with ungrounded delta systems. This is a system problem with ungrounded delta systems. Makes no difference how the motors are connected.
The motors can't tell the difference between power from a star system and power from a delta system. Given three hot wires and a voltmeter you and I can't tell either.
respectfully

RE: Run Wye motors on Delta system?

(OP)
Thank you all for your responses.  My confusion stemmed from some of the foreign motors that we have purchased.  They are marked with delta and wye connections instead of the usual high/low voltage.  Again thanks!

RE: Run Wye motors on Delta system?

Pappafuzzy, now  that is a bit of a different situation.  With motors marked as you describe, you should notice that there is a different voltage rating for the wye and delta connections.  It is very important that you wire the motor in the proper configuration for the voltage that your service provides.

The comments above were more to the point of having two motors, both labelled for the same voltage but internally configured with wye or delta connected stator coils.  In that case, there is no difference since the voltage rating is the same.  In your case, there is a difference since the voltage changes for each configuration.

RE: Run Wye motors on Delta system?

Nema motors use series or paralleled windings for a 2:1 voltage adjustment. IEC motors use delta or wye windings for a 1.73:1 voltage adjustment. Once the motor is connected in wye, you only have three wires to connect to the power and all the previous advice applies.
respectfully

RE: Run Wye motors on Delta system?

If the motors come from a South American supplier you will find that most are wound as Double Why AND Double Delta in order to be able to work with 220V/380V/440V/575V (mostly the 575V conection is there just to be able to use a star delta starter in 440V operation, check your motor plate for the correct connection for each voltage.

We have so many different voltages around here in the different countries that most motors are sold like that.

Regards

SACEM1

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