Line Supply Connecting To Motors 1

[pga.elec]

Have been asked a question which I am not 100% on, and I have never been asked before.

Motors have 6 studs inside the terminal chamber, U1, V1, W1, and then the internal wiring of the motor and the studs on the opposite side of the chamber read W2, U2, and V2. If the motor is a Star configuration, the links are placed across W2, U2, and V2. If it is a Delta configuration, the links are placed across U1 to W2, V1 to U2 and W1 to V2. The line supply cable is connected L1 to U1 stud, L2 to V1 and L3 to W1, and if the motor needs to be reversed, then two of the line phases are swapped.

I have been asked, that due to the tightness of connections, can the line supply phases be connected to the other side connections, W2, U2, V2, and the links changed to the other side if Star configuration. So L1 would connect to U2, L2 to V2 and L3 to W2.

My first thought would be this cannot be carried out like this, but then again, I have never been asked this question. All line supply cables have always been connected to U1, V1, W1 and the links fitted accordingly. Can anyone confirm please and the reasoning whether it is acceptable or not?

Many thanks in advance.

 

[edison123]

Yes, you can interchange supply leads L1, L2 and L3 between U1, V1, W1 or U2, V2, W2 since U1, U2, V1, V2 etc are arbitrarily tagged at the factory. Just check the motor rotation direction (in the motor decoupled condition) when you do the supply lead change from U1, V1, W1 to U2, V2, W2. If the rotation direction is wrong, you swap any two supply leads as you correctly stated.

Muthu

http://www.edison.co.in

 

[waross]

What Edison123 said.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[che12345]

Dear Mr. pga.elec

Q. "... I have been asked, ... can the line supply phases be connected to the other side connections, W2, U2, V2, and the links changed to the other side if Star configuration. So L1 would connect to U2, L2 to V2 and L3 to W2...".
A. For "star" connection:
a)Yes. You may place the links across [U1-V1-W1]; instead of [U2-V2-W2],
b) Yes. You may connect L1-U2, L2-V2, L3-W2; as the links are now across [U1-V1-W1],
c) There is NO (change) in the [direction of motor rotation].
d) If your (supply) [phase sequence] is L1 - L2 - L3 , with above a) and b) connection; the motor rotation (shall be clock-wise); looking at the direction of the [drive shaft] end.
Che Kuan Yau (Singapore)