Installation Rules-past papers.

[ians]

Referenced from SANS 10142-1 (ed 3.1)

b) suitable protection shall be installed; and
c) where, for practical reasons, the supply to the installation cannot be
automatically disconnected by an earth fault current of double the rated
current (or higher) of the main protective device, as an alternative, an earth
fault detection and disconnecting device can be installed at the point of
control of the installation. The earth fault detection and disconnecting
device shall be so installed that they operate at a current related to the
earth loop impedance which will limit prospective touch voltages under
short-circuit fault conditions to 25 V for a period not exceeding 5 s.
NOTE 1 These requirements can easily be achieved by using an earth leakage
device that has a rated earth leakage tripping current (rated residual current) IΔn not
exceeding 300 mA. Devices provided with a time delay of, for example, 0,1 s, will
ensure discrimination with earth leakage protection devices in final circuits.
NOTE 2 Separate earth fault protection could consist of sensitive earth leakage
protection, which might not always be practicable where large currents are involved.

[Gerhard.Oosthuizen]

Thanks. Above question is confirmed.

I also have a another question. When they give any question about estimating loads of the installation they will say for example the following....

Stove supplied with 6 mm square mm with minimum ECC.

My question: What is minimum ECC? In the old days a 4 mm square was fine for a 6 mm square conductor. Most of the previous papers use ECC as 4 mm square.
As I understand the new standard, the earthing conductor will be the same size as the phase conductor.
So I understand that the earth conductor is also 6 mm square mm. Is my assumption correct?

Thanks

[Dylboy]

That's a tricky one in my opinion as a 6mm˛ FTE cable as the ECC as a 2.5mm˛....

The whole thing with the Ecc being same as phase is if it does not form part of the cable is the below, not sure if it is applicable though to that question but sure it plays a role as has length involved

2.1 Earth continuity conductors
6.12.1.1 An earth continuity conductor shall
a) consist of compatible conductors,
b) if it forms part of a cable other than a flexible cable, comply with the relevant
requirements of the standard for the cable,
c) if it forms part of a flexible cable, be of the same material as, and have a
nominal cross-sectional area at least equal to, that of the largest phase
conductor,
d) be able to carry the prospective fault current without excessive temperature
rise of the conducor, within the disconnecting time
e) if it does not form part of a cable or flexible cable, have a nominal cross-
sectional area at least equal to that determined in accordance with table 6.28

More so indent e) and the table on page 167.

But that has more to so with length as well the table...

Sent from my SM-N960F using Tapatalk

[Gerhard.Oosthuizen]

It still confuses me. The length of the ECC will play a significant role in selecting the minimum ECC size.
I am going to use the same conductor size for the ECC than of the live conductor size.
The length of the ECC is critical. Therefore the minimum ECC size cannot be determined.
If the length was known than one can use the following formulae to calculate the minimum ECC size.
Touch voltage = 2 x I (Breaker Size) x R (ECC resistance)
R = (rho x l) / A
From above the area of the ECC can be calculated.
Even in this formulae, length is needed.
Is there anyone with a different idea. I tried to google it but not much is available.

[W-TDMI]

Hi Gerhard.

Use table 6.28(a) of the SANS 10142-1 Ed3. That will help you with the ECC size if its the same size as the PH conductors. Watch this video from our training modules for WIREMANS LICENSE. Hope it helps https://www.facebook.com/TDMITrainin...71562097739711

[ThabangM]

Guys I need some help here.

I'm writing Installation Rules, papers 1 & 2 very soon.
But I need desparately the following documents:

SANS 1973-3
SANS 10198-2
SANS 10198-1
SANS 10292

I have memos and questions papers for both from 2007 that I cann share with anyone in need.
I also have the following study material.
OHS Act 85 of 1993.pdf
OHS Acts, 1993-Construction Regulations, 2003.pdf
OHS Acts, 1993-Electrical Installation Regulations, 2009 .pdf
OHS Acts, 1993-Electrical Machinery Regulations 2011.pdf
SANS-10142-1, 2009.pdf
SANS-10142-2, 2009.pdf
Syllabus, 2009.pdf

Regards
Loyiso

Good day,

I am writing installation rules paper 1 and paper in november. Please kindly assist with the previous question papers and memos. i would also appreciate a study guide. Thank you.