Leccy motor changing from start to delta the hard way.

[Pete.]

I got this star-wound motor that is a particular type and shape that I want to run off a VFD. I've stripped it out and found the star point, cut the ends loose so now I have six wires to play with instead of three.

So here's what I got, I've done a sketch showing the relative positions of the three windings in blue, green and pink .There are 36 winding slots, on each of the three windings one end exits exactly opposite the other as shown below.

I've shown it how it WAS, in star configuration with solid lines going to a junction and the dotted lines show how I plan to connect it for delta. What I don't know is if it matters which way I connect the ends (apart from obviously I mustn't connect the same winding to itself).

 

[Seadog]

Pete, it does matter that all of the coils present a magnetic field of the same polarity, (albeit out of phase) so that the field travels around the yoke. If one of the coils is connected back to front then it will affect the operation, possibly stalling the motor. I think if you keep everything symmetrical as in your diagram you should be OK.

 

[Pete.]

That's what I figured, that symmetry was the key.

 

[Pete.]

Actually, having sat and looked at the sketch it's impossible to get it non-symmetrical without connecting one winding to itself. I think I've worried about nothing.