Level 2 motor assignment question

[bobby]

Had this final assignment chucked on us yesterday with only 2 weeks till end of year at college. Fair enough they wanted to wait until our exams were out the way it is a easy one I suppose, right heres my questions:

On a star and delta circuit layout, what are the 3 terminals reffered to as?

Here's what I'v gathered so far: U1 U2 W1 W2 V1 V2

Would the 2's be in the 3 terminals of the diagram or just the 1's?

Do the 2's just mean the windings?

What order should they be in on the 3 terminals?

Any help or actual an labelled diagram of star and delta would really be appreciated thanks!

 

[NozSpark]

Found this by googling "star delta connections"

www.rotor.co.uk/technical_support/star-delta.pdf

 

[a1]

Noz, I am sure BOB will see the funny side to that first list. Brilliant!

That site is now in my favourites.

 

[Andy™]

www.rotor.co.uk/technical_support/star-delta.pdf

it appears as though they are working to the 18th ed

To change direction of rotation swap any two Life (L1, L2, L3) inlet leads.

 

[bobby]

Thanks for replies I did find out by giving google another bash that the 2s just simply meant the windings and thats the confusion over for me .

The only thing thats stopping me from printing of this assignment is the results power equation.

I'v been given little info about this and just presumed it would be easy but I got myself into a right mess with it, the handout slide says

"Use the following formula to calculate the power values for both star and delta"

"(root squared)3 X V1 X I1"

(and/or?)

"P = 1.732 X IL X VL = ___watts"

this is what I came out with using my results in the table:

delta: P = 1.732 x 412 x 5.1 = 3639.2784watts

star: P = 1.732 x 412 x 1.2 = 856.3008watts

In my testing results table the voltage readings are under VL and current under IL but the formula only asks me for 1 reading ?:|

The problem is delta should be 3 times higher in power value then star which is sort of what mine came out as BUT for this assignment both power results are supposed to be near enough equal so I can then say I suspect a fault has occured in the system blah blah...

when reading the results out to the class my tutor did read out the voltage values as 4.12v instead of 412v It confused me a bit so i got rid of the . in my readings which i know will effect the equation but i have tried both sides of it and no solution. please somone sort me out as you can see somthing probabley so simple has got me in riddles X(

 

[bobby]

Anyone have any ideas on this 1? will have another go at it tommorow until it's sorted has to be in on monday will really appreciate any help.

 

[Apache]

The problem is delta should be 3 times higher in power value then star which is sort of what mine came out as BUT for this assignment both power results are supposed to be near enough equal so I can then say I suspect a fault has occurred in the system blah blah...

Bobby - I know nothing about motors so I can't really help, but the above statement makes no sense!

Consider yourself *bumped*