Is an equipotential zone required for each appliance?
If two appliances are in the same area such as a stunner followed by an immobiliser can I share and electrode and bonding bar for them or much each have it own?
NZS6116 - Equipotential zones
Re: NZS6116 - Equipotential zones
3.4.1 does not specify that each must have an individual bonding system; and it would make no sense to have adjacent appliances connected to different "local" electrodes".
Equipotential bonding - for this Standard or any other - is about not having simultaneously accessible conductive parts at significantly different potentials.
Equipotential bonding - for this Standard or any other - is about not having simultaneously accessible conductive parts at significantly different potentials.
Re: NZS6116 - Equipotential zones
Regardless if shared or not, every animal stunning or meat conditioning appliance must have an equipotential zone, correct?
Re: NZS6116 - Equipotential zones
3.4.1 doesn't say that.
The requirement for EB applies to various metalwork in vicinity; and is not specific to each, or any, appliance.
Note also 3.1.5(b); which permits isolating transformer as alternative to earthing & bonding for fault protection
(using the old terminology: "indirect contact")
Presumably, but not stated, such a tx is intended to be used to provide a separated supply.
This surmise based on the fact that separated supply is accepted as means of fault protection in "3000" [1.5.5.5].
(Another example of poor drafting in this Standard. Isolating transformers are also used to achieve galvanic isolation between different earthing systems ["3004"]. Same device; very different function. We should not be left to infer what is meant.)
If there is no accessible metalwork in vicinity of an earthed appliance, then EB may not be required.
And if the appliance's source is an separated supply, EB serves no purpose.
Eg the possum stunners mentioned in 3.7.2.4;
- unlikely to have any metalwork around them; may even have no accessible conducive parts
- source may not be referenced to (mass of) earth
Still a risk of shock if someone reaches in, but it will be shock between internal parts, not shock between live parts and earth
The requirement for EB applies to various metalwork in vicinity; and is not specific to each, or any, appliance.
Note also 3.1.5(b); which permits isolating transformer as alternative to earthing & bonding for fault protection
(using the old terminology: "indirect contact")
Presumably, but not stated, such a tx is intended to be used to provide a separated supply.
This surmise based on the fact that separated supply is accepted as means of fault protection in "3000" [1.5.5.5].
(Another example of poor drafting in this Standard. Isolating transformers are also used to achieve galvanic isolation between different earthing systems ["3004"]. Same device; very different function. We should not be left to infer what is meant.)
If there is no accessible metalwork in vicinity of an earthed appliance, then EB may not be required.
And if the appliance's source is an separated supply, EB serves no purpose.
Eg the possum stunners mentioned in 3.7.2.4;
- unlikely to have any metalwork around them; may even have no accessible conducive parts
- source may not be referenced to (mass of) earth
Still a risk of shock if someone reaches in, but it will be shock between internal parts, not shock between live parts and earth
Re: NZS6116 - Equipotential zones
The whole of 3.4 seems to apply to every appliance?
I see 3.1.5 (b) specifically mentions it but nothing in 3.4 says it doesn't have to happen if an isolated supply
What about 3.4.4? That indicates regardless of what appliance type or how it's supplied that every piece of exposed metal work must be bonded within 2.5m?
I see 3.1.5 (b) specifically mentions it but nothing in 3.4 says it doesn't have to happen if an isolated supply
What about 3.4.4? That indicates regardless of what appliance type or how it's supplied that every piece of exposed metal work must be bonded within 2.5m?
Re: NZS6116 - Equipotential zones
Section 3 applies to installation of equipment.
3.1 gives the general requirements;
with 3.1.2 permitting (additional) protection against direct contact (now known as "basic protection") to be omitted IF the equipment is Class A and is within an equipotential zone.
(I say "additional" protection, because - as per 1.2 - we still have to meet the underlying provisions of "3000")
3.1.1 gives a top-level requirement;
3.1.2 gives an Exception to this requirement (so should not be a separate clause)
3.1.3 covers the means of providing basic protection, IF it has to be provided.
(3.1.3 is a high-level statement; and should have been part of 3.1.1).
3.1.4 directs us to Table 1 for acceptable means of providing "protection against direct contact" (basic protection)
(Note that the term is defined [1.4], copied (in slightly modified form) from "3000: 2000".)
One problem arises here because fact is that much of the equipment covered by "6116" has readily accessible live parts.
I.e. it doesn't have basic protection; and can't have it - in any of the forms permitted by "3000" [1.5.5] without rendering the equipment ineffective.
Table 1 - supposedly listing acceptable means of providing basic protection - includes items that don't actually contribute to provision of basic protection. In fact almost none of the measures listed can actually provide basic protection that complies with "3000".
Signs, lights, training, etc can arguably reduce the chances of direct contact,
But they don't provide a level of protection that complies with "3000"
So clearly we're not actually talking about basic protection as generally known.
Rather we're talking about alternative methods intended to reduce chance of direct contact with a human.
(Direct contact with livestock can't be avoided; it's what the while world of stunning / conditioning is about)
What we're dealing with is a - necessary - relaxation of the underlying provisions of "3000".
As per 1.2 "any alterations or modifications" to these underlying provisions "are clearly stated"
To which I can only say: "Balderdash!"
A second problem is that , quite simply, bonding of nearby metalwork cannot assist with avoiding/ preventing contact with a part that is normally live.
Accordingly EB should not be listed as a means of protecting against direct contact.
However , pending review of the document by someone with better understanding of earthing & bonding, it is listed;
and we have to work with that
3.1.5 covers the provision of fault protection; gives a choice choice .
Nothing further down can over-ride this choice.
As per option (b); the whole of 3.4 applies for fault protection IF option (b) is adopted; otherwise not.
Which leads to a conflict, where we don't always need EB for fault protection; but we do for basic protection - which it simply cannot contribute to.
All because the writers lost the plot, and forgot the fundamentals of "3000" (which are based on closely similar fundamentals in IEC 60364).
So my answer to your original question was correct:
there is no requirement for each appliance to have its own equipotential zone.
My answer to your 2nd question was correct in that 3.4.1 doesn't set a requirement for every appluance to have a EB zone;
and 3.1.5 includes an alternative to EB for fault protection.
However as currently written; Table 1 requires EB in every (applicable) case.
Despite the fact that it may serve no purpose.
Clearly if there is no metalwork in the vicinity; no EB can be done
--------------------
As I've said before, this Standard is poorly written in many respects;
perhaps because those on the Committee had little experience in writing Standards.
They certainly weren't following the guidelines for writing Standards now provided by SA
(may not have been available in 2006; unsure of when first published
Yes I know it's an NZS, but SNZ still don't have any formal guidelines of their own.
Another example is that 3.1.8 doesn't belong on Section 3 at all.
It has nothing to do with installation; and everything to do with risk assessment [1.8]
where - oddly - there's no mention of the relevant AS/NZSs that outline effects of electricity on humans & livestock
(AS/NZS 60479 series)
--------------
it would be helpful if any future questions included clause references.
It takes time to trawl through trying to identify exactly what question is being asked.
3.1 gives the general requirements;
with 3.1.2 permitting (additional) protection against direct contact (now known as "basic protection") to be omitted IF the equipment is Class A and is within an equipotential zone.
(I say "additional" protection, because - as per 1.2 - we still have to meet the underlying provisions of "3000")
3.1.1 gives a top-level requirement;
3.1.2 gives an Exception to this requirement (so should not be a separate clause)
3.1.3 covers the means of providing basic protection, IF it has to be provided.
(3.1.3 is a high-level statement; and should have been part of 3.1.1).
3.1.4 directs us to Table 1 for acceptable means of providing "protection against direct contact" (basic protection)
(Note that the term is defined [1.4], copied (in slightly modified form) from "3000: 2000".)
One problem arises here because fact is that much of the equipment covered by "6116" has readily accessible live parts.
I.e. it doesn't have basic protection; and can't have it - in any of the forms permitted by "3000" [1.5.5] without rendering the equipment ineffective.
Table 1 - supposedly listing acceptable means of providing basic protection - includes items that don't actually contribute to provision of basic protection. In fact almost none of the measures listed can actually provide basic protection that complies with "3000".
Signs, lights, training, etc can arguably reduce the chances of direct contact,
But they don't provide a level of protection that complies with "3000"
So clearly we're not actually talking about basic protection as generally known.
Rather we're talking about alternative methods intended to reduce chance of direct contact with a human.
(Direct contact with livestock can't be avoided; it's what the while world of stunning / conditioning is about)
What we're dealing with is a - necessary - relaxation of the underlying provisions of "3000".
As per 1.2 "any alterations or modifications" to these underlying provisions "are clearly stated"
To which I can only say: "Balderdash!"
A second problem is that , quite simply, bonding of nearby metalwork cannot assist with avoiding/ preventing contact with a part that is normally live.
Accordingly EB should not be listed as a means of protecting against direct contact.
However , pending review of the document by someone with better understanding of earthing & bonding, it is listed;
and we have to work with that
3.1.5 covers the provision of fault protection; gives a choice choice .
Nothing further down can over-ride this choice.
As per option (b); the whole of 3.4 applies for fault protection IF option (b) is adopted; otherwise not.
Which leads to a conflict, where we don't always need EB for fault protection; but we do for basic protection - which it simply cannot contribute to.
All because the writers lost the plot, and forgot the fundamentals of "3000" (which are based on closely similar fundamentals in IEC 60364).
So my answer to your original question was correct:
there is no requirement for each appliance to have its own equipotential zone.
My answer to your 2nd question was correct in that 3.4.1 doesn't set a requirement for every appluance to have a EB zone;
and 3.1.5 includes an alternative to EB for fault protection.
However as currently written; Table 1 requires EB in every (applicable) case.
Despite the fact that it may serve no purpose.
Clearly if there is no metalwork in the vicinity; no EB can be done
--------------------
As I've said before, this Standard is poorly written in many respects;
perhaps because those on the Committee had little experience in writing Standards.
They certainly weren't following the guidelines for writing Standards now provided by SA
(may not have been available in 2006; unsure of when first published
Yes I know it's an NZS, but SNZ still don't have any formal guidelines of their own.
Another example is that 3.1.8 doesn't belong on Section 3 at all.
It has nothing to do with installation; and everything to do with risk assessment [1.8]
where - oddly - there's no mention of the relevant AS/NZSs that outline effects of electricity on humans & livestock
(AS/NZS 60479 series)
--------------
it would be helpful if any future questions included clause references.
It takes time to trawl through trying to identify exactly what question is being asked.
Re: NZS6116 - Equipotential zones
Sorry to rehash this but I'm still trying to get my head around it
As the standard says, 2 options for indirect protection
Isolating transformer or bonding network
To put what you're saying simply, am I correct in saying then if the transformer is an isolating transformer I can complete omit the eqb requirements of 3.4? Is it actually as simple as a one or the other?
As the standard says, 2 options for indirect protection
Isolating transformer or bonding network
To put what you're saying simply, am I correct in saying then if the transformer is an isolating transformer I can complete omit the eqb requirements of 3.4? Is it actually as simple as a one or the other?
Re: NZS6116 - Equipotential zones
Ah, after a few reads and a good look over the standard I think I understand what you are saying.
So 3.1.2 says if Class A and in a EQB zone the protection against direct contact is not necessary (but references 3.1.1? 3.1.1 talks about working on animals/carcass not direct contact, another mistake?)
Unless Class A and in a EQB zone (3.1.2) or "Stiffeners" in accordance with 3.7.4 direct and indirect contact must be provided, 3.1.4 and 3.1.5 respectively.
3.1.4 takes us to Table 1 unless deviated by section 3.7, Table 1 requires equipotential bonding for every appliance class as per 3.4.
So unless the appliance is a Stiffener in accordance with 3.7.4 or deviated from Table 1 in accordance with 3.7 as 3.1.4 allows then it must comply with the EQB requirements of 3.4?
Although 3.1.5 gives an two alternatives options for indirect contact this is vary rarely an option as almost all appliances will have to comply with Table 1 that already calls for the EQB requirements of 3.4 to be followed?
Basically its a mistake that EQB is listen in table 1 but because it is it's another case of our hands being tied by what the words say.
So 3.1.2 says if Class A and in a EQB zone the protection against direct contact is not necessary (but references 3.1.1? 3.1.1 talks about working on animals/carcass not direct contact, another mistake?)
Unless Class A and in a EQB zone (3.1.2) or "Stiffeners" in accordance with 3.7.4 direct and indirect contact must be provided, 3.1.4 and 3.1.5 respectively.
3.1.4 takes us to Table 1 unless deviated by section 3.7, Table 1 requires equipotential bonding for every appliance class as per 3.4.
So unless the appliance is a Stiffener in accordance with 3.7.4 or deviated from Table 1 in accordance with 3.7 as 3.1.4 allows then it must comply with the EQB requirements of 3.4?
Although 3.1.5 gives an two alternatives options for indirect contact this is vary rarely an option as almost all appliances will have to comply with Table 1 that already calls for the EQB requirements of 3.4 to be followed?
Basically its a mistake that EQB is listen in table 1 but because it is it's another case of our hands being tied by what the words say.