CI Test #1 & Test #4

[bethy]

Why the voltage drop formula to solve these two problem using the "subtract":

V(d) = I * {R*cos(theta) - X* sine(theta)} * L/1000

From table 9, NEC book. It is shown as ( + ). Can some one explain to me please??

Thanks,

 

[bethy]

Oop! Forgot to tell you the problem number; In CI test #2 problem 10 and Test #1 - problem 48. Why the voltage drop formula to solve these two problem using the "subtract":

V(d) = I * {R*cos(theta) - X* sine(theta)} * L/1000

From table 9, NEC book. It is shown as ( + ). Can some one explain to me please??

Thanks,

 

[Raiden]

i am looking at my CI version of the book and tthe answer shows + instead of the - you mentioned. Maybe you have an older version.

 

[bethy]

Rtaiden,

The test was 2011. So it's maybe a error. Would you please give me the answer of those problems with the (+) sign. The one I got the answer goes with th (-) sign. Thanks.

I wonder that Josh had post the correct error on the CI website??

 

[Raiden]

Josh has posted this "Errata" on the website. I have found some other issues that I feel that are errors on the 2012 version.

CI Test #2 Problem 10 Answer: VP = 40 * [0.34 cos (-10) + 0.023 Sin (-10)] = 13.2V then (13.2V/120) * 100 = 11.0%

CI Test #1 Problem 48 Answer: V(d) = I * {R*cos(theta) + X* sine(theta)} * L/1000 =

 

[EItoPE]

Josh has posted this "Errata" on the website. I have found some other issues that I feel that are errors on the 2012 version.

CI Test #2 Problem 10 Answer: VP = 40 * [0.34 cos (-10) + 0.023 Sin (-10)] = 13.2V then (13.2V/120) * 100 = 11.0%

CI Test #1 Problem 48 Answer: V(d) = I * {R*cos(theta) + X* sine(theta)} * L/1000 =

Could anyone please direct me to this "Errata" on Complex Imaginary website? Thanks in advance!

 

[SureLikeStudying]

EltoPE,

Not sure it on their website, I've looked too.

Anyone have a copy of the version 2 errata?

Thanks.

 

[poosri]

So the correct formula is R cos(theta)+ X sin (theta) regardless of lagging or leading pf, correct?