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Discuss I am confused over the wording of Regulation 411.1 in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

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Regulation 411.1 states that:
Automatic disconnection of supply is a protective measure in which:
(i) basic protection is provided by basic insulation of live parts or by barriers or enclosures, in accordance with Section 416, and
(ii) fault protection is provided by protective earthing, protective equipotential bonding and automatic disconnection in case of a fault, in accordance with Regulations 411.3 to 6.

I understood protection against electric shock to be in two categories - (i) protection in no-fault conditions which is provided by stopping persons and livestock actually touching live conductors and (ii) if a conductive part becomes live through a fault then somehow disconnect to ensure that the duration of current flow is limited, mainly through automatic. disconnection.

But Regulation 411.1 seems to imply that Automatic Disconnection of Supply itself includes BOTH basic protection as well as automatic disconnection. Surely Automatic Disconnection involves only (ii)

Jonel
 
Automatic disconnection of supply or ADS does need to satisfy both points i and ii.

It used to be called Earth Equipment bonding & automatic disconnection of supply or EEBADS but apparently people didn't understand it so they changed it to ADS for the simply folk.
 
I understand but if ADS is being defined as requiring (i) and (ii) then why is the phrase ADS used again in (ii), This then becomes recursive and includes basic protection again. So, I feel that the semantics of the definition are confusing.

Jonel
 
ADS is a protective measure which is the combination of two protective provisions, Basic protection and fault protection.

ADS requires,

Basic protection provided by insulation of live parts or by barriers or enclosures; and fault protection provided by:

Earthing, protective equipotential bonding; and automatic disconnection in case of a fault.
 
I suppose it can seem a little confusing.
Just about every protective measure includes basic insulation of live parts.
So what they are saying, is ADS is automatic Disconnection of Supply with basic insulation.
Protective Equipotential bonding is not strictly necessary.
 
I understand all of what you refer to, that was not the point of my original post. Automatic disconnection is being defined by on the very first line of Regulation 411.1. If Protective Equipotential bonding is not strictly necessary then what regulation 411.1 is really saying is that Automatic Disconnection of supply is provided by automatic disconnection!

That was all my original post was trying to make clear.

Thanks everybody for the replies. I just have a little difficulty with the logic of this particular Regulation. I understand the aim of the regulation though and do not disagree with any replies that I have had.

Thanks

jonel
 
I think I get what you're on about: semantics.

Think of "ADS" as a label. Replace it with something else of your choosing: "Large green chicken," for instance. So:

Large green chicken is a protective measure in which:
(i) basic protection is provided by basic insulation of live parts or by barriers or enclosures, in accordance with Section 416, and
(ii) fault protection is provided by protective earthing, protective equipotential bonding and automatic disconnection in case of a fault, in accordance with Regulations 411.3 to 6.

As mentioned above, the label used to be EEBADS which was too much of a mouthful (and too similar to "Ee bah gum" to avoid confusion in all circumstances) so they shortened it to ADS.

Should've gone with LGC in my opinion, but hey.
 
Well, to continue you analogy :-

Large green chicken is a protective measure in which:
(i) basic protection is provided by basic insulation of live parts or by barriers or enclosures, in accordance with Section 416, and
(ii) fault protection is provided by protective earthing, protective equipotential bonding and large green chicken in case of a fault, in accordance with Regulations 411.3 to 6.


This was all I meant. But I will close on this now because I seem to be upsetting people and I had no intention of doing such a thing.

Thank you all

Jonel
 
Your not upsetting anyone mate, it is a bit confusing as it sounds like it contradicts itself.

Automatic disconnection of supply is a technical term we as electricians use that is what the opening statement of the regulation is getting at by calling it a protective measure.
Your mainly see this written on Electrical test certificates abbreviated as ADS.
It could be called anything though like "Large green Chicken"

So In your analogy

Swap Large green Chicken back to automatic disconnection of supply in point (ii) but leave it as Large green Chicken in the opening paragraph.
 
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It‘s all explained in D.W. Cockburn’s “An Illustrated Explanation of Earthed Equipotential Bonding” and “An Illustrated Explanation of Automatic Disconnection of Supply”:tearsofjoy:
 
Automatic disconnection in the case of a fault is a method to disconnect the supply safely.
The protective measure of automatic disconnection of supply includes basic protection, equipotential bonding and automatic disconnection in the case of a fault.

The automatic disconnection in the case of a fault on its own is not a complete protective measure because a protective measure needs to include both basic and fault protection; therefore you add main bonding and basic insulation (or barriers and enclosures) to complete the protective measure.
 

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