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WYE Motor Connections
- Thread starter KMAYEUX
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electricpete
Electrical
I assume what you meant was
"TI, T2, and T6 are connected to the power circuit and T4, T5, and T3 are connected together" ?
Also I assume T1, T2, T6 connected in same rotation sequence as would normally connect T1 T2 T3.
One thing for sure is that you definitely cannot predict any reliable operating mode of the motor. It may overheat and may have abnormal current or vibration or other problems.
With that said, trying to analyse the connection I get an unusual result. You will have converted FROM
a b' c a' b c' etc
TO
a b c a' b' c' etc
The fundamental component of the resulting magnetic field rotates at one-half the original speed. So it seems possible in theory you could have stable operation at one-half motor speed (carrying some load). Surely the harmonic design of the motor would be destroyed and therefore if such stable operation were possible you might likely have some problems with vibration and anomalies such as cogging and cusps in torque speed curve.
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"TI, T2, and T6 are connected to the power circuit and T4, T5, and T3 are connected together" ?
Also I assume T1, T2, T6 connected in same rotation sequence as would normally connect T1 T2 T3.
One thing for sure is that you definitely cannot predict any reliable operating mode of the motor. It may overheat and may have abnormal current or vibration or other problems.
With that said, trying to analyse the connection I get an unusual result. You will have converted FROM
a b' c a' b c' etc
TO
a b c a' b' c' etc
The fundamental component of the resulting magnetic field rotates at one-half the original speed. So it seems possible in theory you could have stable operation at one-half motor speed (carrying some load). Surely the harmonic design of the motor would be destroyed and therefore if such stable operation were possible you might likely have some problems with vibration and anomalies such as cogging and cusps in torque speed curve.
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
electricpete
Electrical
a b' c a' b c' follows in the sequence listed for a c b sequence applied voltage
while
a b c a' b' c' follows in the sequence listed for a b c sequence applied voltage.
So that theoretical 1/2 speed mode I mentioned would also be reversed in direction.
Also if it was successful there would be substantially reduced fundamental primary flux due to lack of constructive addition of adjacent poles. Result is that if the motor could run at half speed, the torque capability would be reduced and horsepower (torque times speed) reduced by factor of more than 2.
I'm a little bit out on a limb on all this. I've certainly never tried it. Interested to hear any other comment on whether a motor could be made to operate in reverse at half speed through intentional miswiring.
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
while
a b c a' b' c' follows in the sequence listed for a b c sequence applied voltage.
So that theoretical 1/2 speed mode I mentioned would also be reversed in direction.
Also if it was successful there would be substantially reduced fundamental primary flux due to lack of constructive addition of adjacent poles. Result is that if the motor could run at half speed, the torque capability would be reduced and horsepower (torque times speed) reduced by factor of more than 2.
I'm a little bit out on a limb on all this. I've certainly never tried it. Interested to hear any other comment on whether a motor could be made to operate in reverse at half speed through intentional miswiring.
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
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