Installation Rules-past papers.

**cvmostert** · 05-Jun-12, 08:54 AM

Originally Posted by deez

hi, can anyone assist with memo's for paper 1 and 2 pls

PM me your email address.

**mbokodas** · 09-Jun-12, 09:06 PM

how much is this study guide?

**deejaypsy** · 26-Jun-12, 11:02 AM

Thanx cvmostert! Papers received. I now have most of the papers with memos from the last 6 years. Anyone with memo's for 2012 and 2011? Cant find them anywhere...

**deejaypsy** · 26-Jun-12, 01:16 PM

Hey guys, i am seriously stuck on probably what is a rather simple question, but i cannot fathom how the memo gets the answer for this one. I suppose this is why you need to attend a college course to pass this exam right??
2nd Paper 2010 August, Question 1.
DB 230V AC supplying: 10m run then splits to 10m run to 20A load, and 20m run to 40A load.
This is all you are given.
Calculate the minimum cable size.
Now i'm assuming this is all 1ph and copper cables as it doesn't say.
The memo gives me an equation to use: VD = (I x pL) / A; therfore, A = (I x pL) / VD
Ok, now first of all, i know that A is the area. I know that I is the amperage. I am assuming that VD is the volt drop?? I have no idea what pL is???
The totals the memo inserts are: A = (I x pL) / VD --- A = (40 x 0.022 x 30) / 5.5
= 4.8mm therefore a 6mm cable should be used.
And further states that a 6mm cable = 0.0073 -- this i understand from Table 6.2(b)
But where do the other totals come from in getting to the 4.8mm cable size??
How does pL = 0.022 x 30??
How does VD = 5.5???
Please could someone explain this to me as i dont know who to ask to clarify this? I have looked back over past exam papers as well, as well as thru my Regs book extensively, but am failing to find any explanation??
The Regs book does not seem to explain the working out behind these answers properly! Or maybe I am just clueless??
Please, any help MUCH appreciated!

**deejaypsy** · 26-Jun-12, 01:35 PM

Another thing...
Just working my way through past papers, and am realising that the number of times the memo sheet is incorrect in its calculations is scary! Are the guys who are marking these papers electrically minded, or are they just paid to sit and mark ONLY according to their answer sheet?? Over the last 4 papers i have worked through, about 10 or 15 marks could have been lost due to an INCORRECT answer sheet!! I am guessing here that if your answers dont match the ones on the memo, u'll be losing your marks?! And, not being allowed to challenge the marking, you'd be doing a rewrite at another R500! Seriously hoping this isn't the case...!!

**jason kyte** · 15-Jul-12, 05:07 PM

Hi

Do have the past papers for August 2010 paper 1 and 2. The memos would be very helpful as well.

Regards

jason

**deejaypsy** · 16-Jul-12, 09:45 AM

Hi there Jason,
I do have both Papers plus Memos.
Send me your email address and i'll get them off to you.
Cheers
Si

**cvmostert** · 16-Jul-12, 11:28 AM

Originally Posted by deejaypsy

Hi there Jason,
I do have both Papers plus Memos.
Send me your email address and i'll get them off to you.
Cheers
Si

Thanks i also have them, saves me some trouble.
Cheers

**jason kyte** · 17-Jul-12, 07:34 AM

Thanks so much.

jason@jkelectrical.co.za

Regards

Jason

**Jacechop** · 17-Jul-12, 10:01 AM

Originally Posted by deejaypsy

A = (I x pL) / VD
Ok, now first of all, i know that A is the area. I know that I is the amperage. I am assuming that VD is the volt drop?? I have no idea what pL is???

Hi there,

From 'first principals' RoH, Radius of Hollow ; R = pl/a . That is (p) the coefficient for copper at 0.022 which will never change and l the length which you take from your question. R (resistance) = VD/I

Hope that helps