I think I’d use a panel key.
So, another change in standards…
SANS10142-1-2 has been removed from the SABS website and none of the lists have it on.
Thus they “removed” the standard as quietly as they “released” it.
As the compliance guy, I will disregard SANS10142-1-2 until it is again in public domain…
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Thank you!
Coming back to this, just want to clarify. This means you’re probably digging up your main supply cable, splicing in two places and sticking this
kind of isolator in a wallbox with a municipal lock?
Basically yes,
However, having spoken to quite a few people and getting feedback from guys who spoke to even more important people, there is a massive push back on this isolator being accessible. The merits of the Isolator is not being questioned. I have one, I think it is a good to have. The position is being argued about like mad.
Its all about that “accessible” part, how to interpret this correctly and SAFELY.
Best would be to (as per plonkster recommendation) is having something like this or similar in a nice metal or PVC box with a panel key. Each property should have an “entry” point somewhere on their boundary. If you are lucky it is in a nice box already and you just add this to it or next to it.
So the crims can just turn your house off. Nice.
Exactly the problem most people have. Thus the metal box with panel key similar to one in the street.
One question here is that the isolator should be lockable and accessible, no-one says it cannot be locked in the “on” position already!
If you have solar and battery storage behind the meter, meh. You will get the LoM warning if someone switched that off… no batteries and at night, yes.
Groetnis
Would that need to break the earth? Then all SSEGs need an additional earth stake.
If it’s TN-C-S, the C part would be broken by that switch. That’s quite bad.
Anyways, assuming there’s an extra pole, you can use that to signal back inside that some switched it off as opposed to the power being out. More wiring though.
No, this is to be after the E-N munic bond. So only breaking Neutral and Live.
I for one is against the earth spike for places like Cape Town…
So lets open a can of worms…
Why install an earth spike? Is there a specific reasons?
One of the main reasons I am against the earth spike is that you are now messing with fault levels…
Fault levels? But I only care about my house! Well, with an earth spike the neighbourhood also cares about your house!
So without going into the details, as I do not have my Power Systems engineering handbook next to me, the earth and neutral is the same thing, however usually you do this via an “earthing resistor” this limits the earth fault on the “system”.
Now what happens if you earth spike is that the earth fault now have a very low resistance path to ground. So your neutral currents during fault will be substantial. The entire neighbourhoods fault is going into your system… And then things start burning.
Yes, if the earth spike is at the munic boundary it is safer if it is not there it is the best!
Also, people doing earth spikes never check if the earth resistance is perfect and it ends up being a bunch of floating copper in a hole etc…
True, except for you now trust the munic to provide proper earth and at best as I have seen, that is frequently a big problem. Their earth’s in various place is not always proper, seen as those are almost never maintained. Lots of substations and mini subs in older Neighbourhoods are not properly earthed no more. YMMV
Agreed tho that many diy earth installs leave a lot to be desired.
Groetnis
But hey, earthing is not complicated now innit? 
All jokes aside, it’s a complex subject in relation to the grid and protection, especially in front of the meter.
Groetnis
So our bonds are actually outside the boundary wall? All the TN-C-S explanations I’ve seen looked like it happened in the DB. Mostly UK stuff though. Edit: Actually at their meter box, which is on the boundary.
Yeah, … because the Munic’s earthing was not “working” since long before the 1st Multigrid was grid-tied, having immense issues, that we’ve found that problem.
Munic is not interested in responding … and the best of all, the box in the street, always open.
So yeah, the problem has now moved to the neighbour’s property, on the boundary, where the TN-C-S is now
As far as I know, you never ever break/switch the earth connection. That’s like a rule… just imagine a malfunction in that switch. I don’t even want to.
Yeah, that was where my head was going. But if the point of the switch is to isolate because you don’t trust things on the other side of the boundary, then I’m not sure.
History (and policy) is full of great ideas that don’t actually work on the ground.
I am not lucky. There is no box on my outer wall. The nearest thing that looks like a point of connection is on the North West corner of the house behind a small panel. To fit such a switch to my house would require either 1) digging up the cable from the council, fitting a box on the outside wall, or 2) routing a thick and expensive cable from the present connection point to the outside wall and back (some 20 meters). Option 1 is obviously better.
Now since they will also be swapping us over to prepaid, and since I see this box-on-the-outside-wall already in my neighbourhood (with the prepaid meter peeking out through a small clear window), I do suspect this is going to happen anyway.
Hmmmm:
B.3.2.1 All alternative systems shall have an own earth electrode connected to the consumer’s earth terminal and shall comply with 7.12.3.1.1 in SANS 10142-1:2012.
• B.3.2.2 Embedded generators need not have their own earth electrode in accordance with SANS 101421, but an own earth electrode is preferred.
Was this revised?
Groetnis
Which version and which standard are you quoting here? This looks like the “old” revision of 10142-1-2?
Yes, it has been revised and can be found in newest ed.3 of SANS:
If you read it in conjunction with TN-C-S methodology you will see why.
SANS10142-1-2 (the published and then removed version) is quiet on the earth spike/electrode to be installed. It again only mentions that is shall be bonded to the earth terminal:
From “main” SANS
There are many “if required” or “may install” in the documents. But nowhere is it said to have to be installed.
If your “council” earthing is terrible, I would recommend going to the outside box with a big hammer, a 10m copper pole (or 3 if you are doing crow’s foot) and hit it in there and bond that to the council E-N bond where it goes into your property. Yes, that will increase the areas fault currents, but not into your system…
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And suddenly your neighbour’s earth leakage starts tripping. Thanks man!
