Star Delta starters

Can any one help me, I have been asked to connect a 10 HP motor to an old manual rotary star delta starter, there is obviousely no diagram with it only a legend with connections s through to z, I would assume that U V W are the motor connections but want to be 100% sure before I attempt it.
Any info would be gratefully received.

Paul

100% this is not the right connecting diagram.
you can look here .
you have to wire all the motor connections U1,V1,W1,U2,V2,W2 to the star-delta starter.
better read, google search .. who is the manufacture of the star-delta switch? may be he still keeps the same connection diagram-search for manuals

I would guess that the markings will be R S T, U V W, X Y Z. R S T are the Line supply, U V W are one end of the windings X Y Z are the other. So windings are U to X, V to Y and W to Z. If there are auxiliaries then you will have to figure them out yourself because there are so many options. Make sure that the system using the switch meets current specs, as by fitting the new motor you are probably accepting responsibility for the job.

Sometimes there is a combination of letters/numbers for example R/L1 or U/T1, the important bits are the R and the U. As bio says sometimes they use U1 V1 W1 and U2 V2 W2 and if you have a long memory then A1 B1 C1, A2 B2 C2 were quite common.

Good luck

Bryan

Bio, great link, I have a hardcopy of that book.
But as it is a manual rotary switch, this page is more fitting:
http://www.wiringmanual.com/rotary006.html
Unfortunately the terminal numbers are not the same as the ones Paul list.

So I vote with Bryan.
Before connecting it up, you should be able to meassure if Bryans assumption is correct.

In Y there must be connection through:
R-U
S-V
T-W
X-Y-Z

In D there must be connection through:
R-U-X
S-V-Y
T-W-Z

Hi Jesper

Nice try but no coconut, Star/Delta causes more trouble than almost any other motor connection. There is no crossover of phases in your Delta connection so you have Line 1 (R) going to both ends of the same phase same for S and T

There are I think two possible correct Delta connections to maintain the correct rotation but please feel free to correct me.

R-U-Y
S-V-Z
T-W-X

R-U-Z
S-V-X
T-W-Y

Bryan

Hi Bryan.

Noone knows what X-Y-Z really correlates to.
Probably X=U2, Y=V2, Z=W2 and then you are correct.
But it could also be X=V2/W2, Y=W2/U2, Z=U2/V2 and then I am correct.

Better is to establish the truth by measuring.

guys you're both right. the idea is that Paul Brooks don't have a clue about AC motors, star-delta starters and so on. so if he is not qualified enough it's not recommended to wire the motor but to search for help from electrician.
i have an additional question: if there is a 3 phase motor without terminal legend, you can simply find out the 3 phase pairs. but can you determine which is start and end of the windings U1-U2, V1-V2 and W1-W2 ?

bio said:

i have an additional question: if there is a 3 phase motor without terminal legend, you can simply find out the 3 phase pairs. but can you determine which is start and end of the windings U1-U2, V1-V2 and W1-W2 ?

Click to expand...

Bio, maybe this will help
http://www.plctalk.net/qanda/showthread.php?t=434
http://www.plctalk.net/qanda/showthread.php?t=26854&highlight=lead+motor