Wye/Delta voltage

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Bigbossman

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I need to install a 2 HP 3 phase motor 230/190v. There is an existing disconnecthat has 195v per phase, The supply voltage 120/208 goes through a buck boost step up transformer. The transformer however is Delta but the input voltage is Wye. The input has no neutral and motor does not require one. Two questions is the 195v on the secondary considered Wye voltage or Delta voltage and will the motor work properly with the voltage?
 
LarryFine

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With the voltages you're reading, it sounds like the buck-boost is being used to drop the voltage.

I recommend removing it and running the motor on the full 208v. It'll run cooler and use less current.
 
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jim dungar

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Your transformer is connected line-line so the output should be treated like a delta (do not bring the neutral to the load) It is not an isolation transformer so it is more appropriate to refer to it as having Low Voltage and High Voltage connections as opposed to primary and secondary.
 
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Bigbossman

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LarryFine said:
With the voltages you're reading, it sounds like the buck-boost is being used to drop the voltage.

I recommend removing it and running the motor on the full 208v. It'll run cooler and use less current.
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The
jim dungar said:
Your transformer is connected line-line so the output should be treated like a delta (do not bring the neutral to the load) It is not an isolation transformer so it is more appropriate to refer to it as having Low Voltage and High Voltage connections as opposed to primary and secondary.
Click to expand...
ActionDave said:
And the motor only cares about voltage level, not if the source is wye or delta. 195V is pretty low but may work.
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why does the motor say 230/190 i thought the the first number was a wye connectior and the second delta is that not correct? If not what the differerence between the two?
 
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Bigbossman

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ActionDave said:
It almost sounds like the source voltage changed from 240 to 208 and the buck/boost stayed in place.
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The source voltage is 208 the buck boost say 208 to 230 on the label but its not coming out at 230v only 195v thats why i was wondering if the
208/120v being wye and the transformer saying that its delta caused it to only come out 195
 
synchro

synchro

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Perhaps 190V is the spec when used with a 50 Hz supply since 230V x 50Hz/60Hz = 192V

Like Dave said a nameplate pic would be helpful.
 
ActionDave

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Bigbossman said:
The


why does the motor say 230/190 i thought the the first number was a wye connectior and the second delta is that not correct? If not what the differerence between the two?
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No. I think Syncro is correct, the 190V is for 50Hz.

The motor windings internally wound wye but that has no bearing on the voltage that feeds it. the only thing that matters is the voltage level.
 
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jim dungar

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Bigbossman said:
The source voltage is 208 the buck boost say 208 to 230 on the label but its not coming out at 230v only 195v
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You most likely have your incoming voltage on the HV leads so what you are getting out is LV. Swap your incoming to the LV connections and your output to the HV.
 
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