question for the experienced or recently qualified sparky

[timhoward]

Hi happyHippyDad,
Sorry for the out-of-the blue message
Just saw your message re maths questions...as it happens I have one!
Just flicking through the Electrical installations Calcs book 10th edition trying to get my brain back into maths and I'm stumped with one (prob easy question - attached) are you, or anyone else you can think of, able to point me in the right direction, the phrase 'wood for the trees' comes to mind! and I'm almost at the scream 'WHY' at the sky on my knees stage, which I one down from throwing myself on the floor in tears lol.

regards
Rozza72

I haven’t had time to check it thoroughly but first suspicion is that the difference is caused by your rounding
You have:
8/65=0.123
Have you tried using the full value of
0.123076923076923 in your calculations?

 

[rozza72]

I haven’t had time to check it thoroughly but first suspicion is that the difference is caused by your rounding
You have:
8/65=0.123
Have you tried using the full value of
0.123076923076923 in your calculations?

Interesting i’ll give it a whirl, thanks for taking a look

 

[Pete999]

Hi happyHippyDad,
Sorry for the out-of-the blue message
Just saw your message re maths questions...as it happens I have one!
Just flicking through the Electrical installations Calcs book 10th edition trying to get my brain back into maths and I'm stumped with one (prob easy question - attached) are you, or anyone else you can think of, able to point me in the right direction, the phrase 'wood for the trees' comes to mind! and I'm almost at the scream 'WHY' at the sky on my knees stage, which I one down from throwing myself on the floor in tears lol.

regards
Rozza72

 

[Biff61]

Algebra and trig are both relevant to electrical theory.

there are of course many rules of thumb and tabulated information that may be used far more often in your working life, however it is important to show you understand how these things can be calculated because some jobs don’t fit the standard circuit arrangements that have all been pre calculated.

Oh so true, it's 40 years ago since I did any trig in tech during my apprenticship, but last week I actually had to drag it out from the recesses of my remaining brain cell to calculate the current in the neutral on a facility and use graph paper.
My head was spinning after a while, would have been nice to have a clamp meter, would have made my life so easy.