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Good morning to you, Dave. Happy weekend.
The lawn is waiting for me to be mowed after some good rains, but first onto more serious stuff.
Interesting subject which I think deserves some more debate and discussion.
There are reasons why certain regulations have been put in place.
I am one of those who not only wants to know what the regulations say, but also the reason/s behind such regulation.
As far as conductor identification is concerned, why is special mention made of multicore cables ?
My take is as follows:
There are only 2 sections of a multicore cable where conductor identification is of importance ie. the ends where the conductors protrude.
What happens along the length of the cable is of little importance as the conductors are 1) invisible and 2) not easily accessible.
The same cannot be said for a single conductor that is both visible and accessible along it's entire length.
How many times have I come across a single phase DB supplied with a 3 core cable where the red is used for supply, blue for neutral and white for earth.
What would now be the right approach assuming that the cross section of the conductors are sufficient for the intended purpose ? To replace the cable ? No.
1. The blue conductor is made black with either tape or heatshrink for the neutral and
2. The white conductor is made green/yellow as above for the earth.
Acceptable ? I would say "yes" as per 6.3.3.2(4)
Now we have a situation.
The earth conductor, even although the ends are clearly identified green/yellow, is actually white. Is this of importance ? I would say "No" because it cannot be seen and is not easily accessible. Likewise, the neutral, black at the ends, but blue inside the cable, according to regs is acceptable.
This is my understanding of why a clear distinction is made in the regulations between identification of single conductors and those housed in multicore cables.
This is also the reason that I, with a clear conscience, use cabtyre for day/night sensors after changing the colour of the green conductor protruding from the cable to red by using heatshrink.
Maybe some of the other toppies can comment.
BTW I do agree that single green/yellow conductors not forming part of a multicore cable should under NO circumstances be used as live conductors.
Peace out ... Derek
Last edited by Derlyn; 21-Nov-20 at 12:47 PM.
Hi
Don't understand the confusion - As Dave stated above it is pretty clear by using the words " Shall NOT " and " under no circumstances" - The NOT is in capital letters and bold in the regulation.
I see the multi core cable , like a 7 core armour cable , which does not come at all with a Green/yellow being marked at the ends to show the earth - In the old days a multi core armour cable used to come with all the wires black and numbered.
To take a green yellow and marked it as a phase cannot be legal especially since it is emphatically stated that it " Shall NOT be used under any circumstance " - Only having a 3 core piece of cabtyre lying loose in the bakkie cannot change the " under any circumstances " clause even if it is marked.
I believe that an AIA would fail the installation.
The way I understand interpretation of the code is that we need to ensure that what we do complies with all the applicable clauses. Quite often where I see an argument about a "grey" area, if one looks closely there has been an interpretation such that an applicable clause has been ignored, or there is a claim that one clause trumps another.
The classic example is earthing of electrical equipment -
6.12.3.1 The following conductive parts shall be earthed:
e) earthing terminals of all permanently connected electrical equipment and appliances;
But despite this some contractors deem they don't have to connect downlighters with earth terminals to earth because -
6.12.3.2 The following conductive parts do not need to be earthed:
b) exposed conductive parts of fixed electrical equipment that are:
1) out of arm's reach from the floor (or walking) level,
2) out of arm's reach from a structure that is bonded to earth, and
...
If 6.12.3.2 commenced with "Despite the provisions of 6.12.3.1" they would have a case. But reality is the installation needs to comply with both clauses. The solution is simple - electrical equipment with an earth terminal needs to be connected to earth.
An example of a specific exception is 7.1.5.1 which is very specific -
7.1.5.1 Except in the case of isolated supplies, an earth continuity conductor shall be connected to the earth terminal of class 1 fixed appliances in a bathroom.
This, quite clearly, is intended to trump the requirement of 6.12.3.1.e.
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Dave
Your interpretation and mine differ somewhat.
6.12.3 Earthing of exposed conductive parts
6.12.3.1 The following conductive parts shall be earthed.
a) all exposed conductive parts of an installation other than those described in 6.12.3.2.
6.12.3.2 The following conductive parts do not need to be earthed.
6.12.3.2 then goes on to list a number of conductive parts that do not need to be earthed.
If one had to interpret the regulations your way then 6.12.3.2 would never apply to any situation.
My question is ... Why is it there ?
Peace out ... Derek
@ GCE. I've never owned a bakkie.
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Another common problem I find a lot ... the bare earth of twin + E with red insulation tape ... used as the return on a PEC (day/night switch) ... not yellow and green ... but if I recall the insulation properties come into play.
Comments are based on opinion...not always facts....that's why people use an alias.
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GCE (28-Nov-20)
That is why I have said in the past that this forum is "lekker".
Debating regulations and the interpretation of same can only be benificial to us all.
Regarding this one, Dave, I must concede you are correct. Not the part about intentionally misrepresenting the regulations, though.
I think it's more out of ignorance than intent to misinterpret the regulations.
I can understand electricians who use regulation 6.12.3.2 (1) in their defence when it comes to downlights or ceiling lights in general because most of the new fitting available are supplied with 2 pigtails and even although they are aluminium, in the case of downlights, or metal bases for most of the round ceiling lights, no earthing terminal is provided.
What swayed me though is the geyser, which is also out of arms reach in the attic. I'm sure the authors of the regulations did not intend that geysers need not be earthed because they are out of arm's reach.
That said, the regulations, in my humble opinion, could do with 6.12.3.2 (b) 1 & 2 totally omitted.
Now, what to do about them lights that are sold without earthing terminals ? Doubt whether that's going to change any time soon.
Now, let me go and wash that egg off my face ..
It's Saturday and that lawn is waiting for me again.
Peace out ... Derek
Last edited by Derlyn; 28-Nov-20 at 07:13 PM.
Dave A (28-Nov-20)
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