pefc problem

[searley]

need some help with Q 3.

i have got the first part i need to no how the answer to the garage is 230 over 0.38ohms how do i get the 0.38ohms ?

 

[kme]

Length of submain conductors (15m 4mm & 15m 2.5mm) at a combined total of 12.01 mohms/M.

do the sum, convert to ohms and add Ze at origin.

OK?

 

[Andy™]

where does 0.38 come from?

Q3 - ze at intake is 230 / 0.2 = 1150A

Zdb is 230 / 0.38 = 605A

to get 0.38

4mm = 4.61 x 15 / 1000 = ???

2.5mm = 7.4 x 15 / 1000 = ???

total = ???

Zdb = Ze + R1R2 = 0.38 ohms

 

[kme]

Thats what I said......

(I just left the O/P do a little of the maths himself)

 

[Andy™]

Thats what I said......(I just left the O/P do a little of the maths himself)

you hadnt replied when i started typing all that! (and ive removed some of the numbers!)