5033 2012 4.4.2.3 says "All PV array protective equipotential bonding conductors shall comply with the material,
type, insulation, identification, installation and connection requirements specified in
AS/NZS 3000, Section 5."
4.3.6.2 details type of cables used in array
I always thought 4.3.6.2 applied to all cables in the array including earth's etc but I have been told it is only for the DC side of things and that 4.4.2.3 above is the requirement for earth's
Am I correct or is what they are saying true?
Earth wire type for PV Array
Re: Earth wire type for PV Array
In my view both clauses apply
Nothing in 4.3.6.2 says the clause doesn't apply to earthing cables.
Comes down to whether 'used within the PV array' is interpreted as including PECs / & bonds.
These conductors are installed in the same conditions as the module / string / array conductors, so should be selected for those conditions.
That said, not every requirement listed would be applicable.
Nothing in 4.3.6.2 says the clause doesn't apply to earthing cables.
Comes down to whether 'used within the PV array' is interpreted as including PECs / & bonds.
These conductors are installed in the same conditions as the module / string / array conductors, so should be selected for those conditions.
That said, not every requirement listed would be applicable.
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Re: Earth wire type for PV Array
Exactly my thinking, appreciate the input
Feels like it's just you and me around here these days Alec haha hopefully not boring you too much
Feels like it's just you and me around here these days Alec haha hopefully not boring you too much
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Re: Earth wire type for PV Array
This is true! I'm going to throw some promo up on the Electricians Community NZ facebook page to remind people of the wealth of knowledge in here, I definitely prefer the forum I wish more people did
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Re: Earth wire type for PV Array
Rehashing this as it's driving me mad. I'm receiving a lot of push back on the fact I've been asking for the earth cables to be flexible and UV rated.
Apparently according to multiple Inspectors and Electricians both AU and NZ seem to deem this over the top and a standard stranded conduit wire is sufficient.
5033:2012
I've reviewed 4.1 and 4.3.3.1
Also 4.3.6.2 but I'm getting told to look at the definition of PV array as defined in this standard and that the earthes aren't part of the PV array
Also 4.3.6.3.1 may have some relevance.
3000:2007
No specific clauses other than general requirements of 3.3.1 and the 3.3.2 sections but if 5033 is indicating such risks I'd expect 3000 to also expect the same level of care.
5033:2021
Although uncited, as you say Alec can be good for looking at intention.
Once again, 4.1
4.4.1
But then 4.4.2.1 makes it clear these requirements are not for earth's and to apply 3000, both in the initial statement and via a note mentioning the use of standard stranded ro be fine.
Is it fair to fail a PV installation for not using such earth? Or am I being over the top?
Apparently according to multiple Inspectors and Electricians both AU and NZ seem to deem this over the top and a standard stranded conduit wire is sufficient.
5033:2012
I've reviewed 4.1 and 4.3.3.1
Also 4.3.6.2 but I'm getting told to look at the definition of PV array as defined in this standard and that the earthes aren't part of the PV array
Also 4.3.6.3.1 may have some relevance.
3000:2007
No specific clauses other than general requirements of 3.3.1 and the 3.3.2 sections but if 5033 is indicating such risks I'd expect 3000 to also expect the same level of care.
5033:2021
Although uncited, as you say Alec can be good for looking at intention.
Once again, 4.1
4.4.1
But then 4.4.2.1 makes it clear these requirements are not for earth's and to apply 3000, both in the initial statement and via a note mentioning the use of standard stranded ro be fine.
Is it fair to fail a PV installation for not using such earth? Or am I being over the top?
Last edited by JamieP on Tue Feb 20, 2024 1:33 pm, edited 1 time in total.
Re: Earth wire type for PV Array
Hi Jamie, my take on it is the earths do not have to be flexible according to 5033:2012 and I have never insisted on it, so I am now hoping my past inspections are ok.
There is not much price difference between stranded and flexible these days.
Clause 4.3.6.2 in 5033 is about the DC cables, hence the diagrams etc.
The definition of "PV Array" is about the components up to the DC input terminals of the PCE and definition of PV Array cable is "the output cable of a PV Array that carries the total output current of the array".
There is not much price difference between stranded and flexible these days.
Clause 4.3.6.2 in 5033 is about the DC cables, hence the diagrams etc.
The definition of "PV Array" is about the components up to the DC input terminals of the PCE and definition of PV Array cable is "the output cable of a PV Array that carries the total output current of the array".
Re: Earth wire type for PV Array
Hi Jamie,
I struggle to see how equipotential bonding wires are thought to be excluded from the definition of a PV array.
Just look at the items that are excluded by the definition i.e. “PV Array foundation, tracking apparatus, thermal control and other such components”. Not one of these items are discussed or specified in the standard; they are excluded from this document.
Equipotential bonding however,is included in the standard and so to my understanding falls under the “all components” that are in the definition.
That being said, clause 4.4.2.3 (last paragraph) appears to support the view that compliance with 3000 is all that is required for the bonding conductors.
I struggle to see how equipotential bonding wires are thought to be excluded from the definition of a PV array.
Just look at the items that are excluded by the definition i.e. “PV Array foundation, tracking apparatus, thermal control and other such components”. Not one of these items are discussed or specified in the standard; they are excluded from this document.
Equipotential bonding however,is included in the standard and so to my understanding falls under the “all components” that are in the definition.
That being said, clause 4.4.2.3 (last paragraph) appears to support the view that compliance with 3000 is all that is required for the bonding conductors.
Re: Earth wire type for PV Array
Perhaps relevant that no particular degree of flexibility of specified; just 'multistranded'.
Unlike latest draft of IEC 60364-7-x for transportable structures which calls for bonding conductors to be Class 5 flexible [to the relevant Standard]
And unlike where other AS/NZS say flexible... complying with [Standard].
So I'll plump for the key being 'multistranded' - ie NOT a single-strand construction.
Similar to '3001"; which specified "minimum 7 strands" for all cabling.
Unlike latest draft of IEC 60364-7-x for transportable structures which calls for bonding conductors to be Class 5 flexible [to the relevant Standard]
And unlike where other AS/NZS say flexible... complying with [Standard].
So I'll plump for the key being 'multistranded' - ie NOT a single-strand construction.
Similar to '3001"; which specified "minimum 7 strands" for all cabling.
Re: Earth wire type for PV Array
The UV suitability is also interesting because 3000 only really deals with direct sunlight in 3.2. Where as other parts of 5033 discuss reflected UV in terms of cable supports and not using plastic ties
Maybe I need to drop my expectations to any stranded cable and only needing UV protection (which could be in the form of conduit or other options) when exposed from under the array
Maybe I need to drop my expectations to any stranded cable and only needing UV protection (which could be in the form of conduit or other options) when exposed from under the array
Re: Earth wire type for PV Array
Interesting point by Jamie M about the definition of "array"; but while the EBCs are not specifically excluded they are also not specifically included.
And when you look at def. of "array cable" it clearly does not include EBCs.
There's general rule that when writing Standards; if you mean the same thing, then use the same wording.
Following that, we arr4e entitled to assume that where different words are used, they mean something different.
4.3.6.2 doesn't use "PV array cables"; it says "cables used within the array."
So logically we should interpret that as wider than just PV array cables", and so wold include EBCs.
Assuming that EL 042 were following the normal rule when drafting this bit.
That still leaves it open to interpretation as to how flexible the cables must be.
It's not as if there's likely to be a lot of movement; and forming 'pig tails' adjacent to connections has long been recognised as a suitable way of dealing with minor movement / vibration.
There's always the option of asking the relevant Committee what they meant by "flexible".
And when you look at def. of "array cable" it clearly does not include EBCs.
There's general rule that when writing Standards; if you mean the same thing, then use the same wording.
Following that, we arr4e entitled to assume that where different words are used, they mean something different.
4.3.6.2 doesn't use "PV array cables"; it says "cables used within the array."
So logically we should interpret that as wider than just PV array cables", and so wold include EBCs.
Assuming that EL 042 were following the normal rule when drafting this bit.
That still leaves it open to interpretation as to how flexible the cables must be.
It's not as if there's likely to be a lot of movement; and forming 'pig tails' adjacent to connections has long been recognised as a suitable way of dealing with minor movement / vibration.
There's always the option of asking the relevant Committee what they meant by "flexible".
Re: Earth wire type for PV Array
Section 4.3.6 in 5033 about Cables
4.3.6.1 then is about cable size for PV string cables, PV sub-array cables and PV array cables .....
Then 4.3.6.2 is about the type of cables used within the PV array
The definition of "PV string cable" clause 1.4.56 is "a cable interconnecting the modules in a PV string or connecting the string to a junction box, combiner box, PCE or other dc loads Refer to figs...."
Then 4.3.6.3 is about installation method
So I interpret the above is about the DC cables, thoughts?
4.3.6.1 then is about cable size for PV string cables, PV sub-array cables and PV array cables .....
Then 4.3.6.2 is about the type of cables used within the PV array
The definition of "PV string cable" clause 1.4.56 is "a cable interconnecting the modules in a PV string or connecting the string to a junction box, combiner box, PCE or other dc loads Refer to figs...."
Then 4.3.6.3 is about installation method
So I interpret the above is about the DC cables, thoughts?
Re: Earth wire type for PV Array
Agree 4.3.6 covers "cables" being a subclause of 4.3 "component requirements".
As it's the only subclause of 4.3 that deals with "cables"; have to assume it covers ALL cables that are poaret of an array.
Which would logically include EBCs as well as the d.c. "PV array c.
In 4.6.3.1 "size", sizes are specified for cables used for three specific functions (regardless of where the are located).
If 4.3.6.2 was intended to apply only to those same three functions; then should have used the same words.
Instead, different wording has been used, but limited to 'within the array" (presumably because that's where the particular conditions being guarded against occur)
The natural conclusion is that 4.3.6.2 applies to more cable functions than 4.6.3.1.
Which to me must include EBCs "within the array" - which after all are subject to same conditions as any other cable "within the array"
Then in 4.6.3.3, different words again, and clearly applies to ALL cabling , whether 'within the array" or elsewhere.
There's also clearly different wording for item (d); which applies to "LV string cables" and also to "LV d.c. cables in domestic";
but not to other cable functions.
So I don't think it's valid to argue that the provisions of 4.3.6.2 don't apply to EBC cables.
And while there may be some room for interpretation about what degree of 'flexible" is required;
it's not much room because they have clarified (at least partially) by saying "multistrand".
They've also stated the purpose of the flexibility requirement; ie to allow for thermal / wind movement of arrays / modules.
So only a limited degree of movement to be accommodated.
Also worth noting is that SWA cables are specifically permitted, by item (g)
Accordingly if the EBC is multi-stranded, I believe it meets the "flexible" requirement of 4.3.6.2 (c).
As it's the only subclause of 4.3 that deals with "cables"; have to assume it covers ALL cables that are poaret of an array.
Which would logically include EBCs as well as the d.c. "PV array c.
In 4.6.3.1 "size", sizes are specified for cables used for three specific functions (regardless of where the are located).
If 4.3.6.2 was intended to apply only to those same three functions; then should have used the same words.
Instead, different wording has been used, but limited to 'within the array" (presumably because that's where the particular conditions being guarded against occur)
The natural conclusion is that 4.3.6.2 applies to more cable functions than 4.6.3.1.
Which to me must include EBCs "within the array" - which after all are subject to same conditions as any other cable "within the array"
Then in 4.6.3.3, different words again, and clearly applies to ALL cabling , whether 'within the array" or elsewhere.
There's also clearly different wording for item (d); which applies to "LV string cables" and also to "LV d.c. cables in domestic";
but not to other cable functions.
So I don't think it's valid to argue that the provisions of 4.3.6.2 don't apply to EBC cables.
And while there may be some room for interpretation about what degree of 'flexible" is required;
it's not much room because they have clarified (at least partially) by saying "multistrand".
They've also stated the purpose of the flexibility requirement; ie to allow for thermal / wind movement of arrays / modules.
So only a limited degree of movement to be accommodated.
Also worth noting is that SWA cables are specifically permitted, by item (g)
Accordingly if the EBC is multi-stranded, I believe it meets the "flexible" requirement of 4.3.6.2 (c).
Re: Earth wire type for PV Array
Thanks Alec for your comments and clarifying.
I haven't seen solid core conductors since the 70's and I can't recall 4mm and 6mm conduit wire been solid cores.
I assume the writers of the standard know what they are thinking but hard to put into words at times and/or errors can be made.
As its been mentioned previously, 5033:2021 the writers clarify it better in clauses 4.4.2 and note 6 and clause 4.6.
I haven't seen solid core conductors since the 70's and I can't recall 4mm and 6mm conduit wire been solid cores.
I assume the writers of the standard know what they are thinking but hard to put into words at times and/or errors can be made.
As its been mentioned previously, 5033:2021 the writers clarify it better in clauses 4.4.2 and note 6 and clause 4.6.
Re: Earth wire type for PV Array
Certainly errors can be made; or desired outcome not expressed clearly enough.
Part of the problem is that Committee members know what they meant, and always think they have said it clearly.
(myself included - though not for this one)
No writer should ever be the proof-reader for their own stuff.
But that's largely what happens with Standards
Similarly no equipment designer should ever be the writer of the manual.
The PC process allows others to point out that maybe another interpretation can be taken
- but then that reader may also think that their interpretation is the only one, and so may not bother making a submission.
Overall very few people bother to get involved in the Public Comment process.
Perhaps the time has come for someone with a dog in this fight (so not me) to ask EL 042 what exactly they intended this rule to mean?
Part of the problem is that Committee members know what they meant, and always think they have said it clearly.
(myself included - though not for this one)
No writer should ever be the proof-reader for their own stuff.
But that's largely what happens with Standards
Similarly no equipment designer should ever be the writer of the manual.
The PC process allows others to point out that maybe another interpretation can be taken
- but then that reader may also think that their interpretation is the only one, and so may not bother making a submission.
Overall very few people bother to get involved in the Public Comment process.
Perhaps the time has come for someone with a dog in this fight (so not me) to ask EL 042 what exactly they intended this rule to mean?
Re: Earth wire type for PV Array
Cheers Alec, I don't mind asking at all, I googled EL-042 committee and that directed me to the Aust Standards web site but I couldn't log in (using an old login) and not given the opportunity to create a new account.
I have emailed them asking how I can get in contact with someone on the committee, so I will wait and see, I have also emailed someone who help develop 5033:2021.
As the standard is 12 years old, I wonder if the committee members who wrote it are still contactable?
I have emailed them asking how I can get in contact with someone on the committee, so I will wait and see, I have also emailed someone who help develop 5033:2021.
As the standard is 12 years old, I wonder if the committee members who wrote it are still contactable?
Re: Earth wire type for PV Array
I just talked to Glen Morris yesturday about this who is a member of EL-042
I didn't get clarification on whether this was the case still in 2012 but he did say that conduit wire, provided it is stranded is suitible for PV array earthing or bonding as per 5033.
I didn't get clarification on whether this was the case still in 2012 but he did say that conduit wire, provided it is stranded is suitible for PV array earthing or bonding as per 5033.
Re: Earth wire type for PV Array
Yes, I was in contact with Glen Morris yesterday, Glen is a very well respected for his solar knowledge here and Australia and some of you like myself may have attended his courses and online trading sessions over the years.
Glen is the Smart Energy Councils rep on EL-042, EL-005 and NT-001 is comments in an email to me are:
“There is nothing specific about the type of earth conductor used for equip bonding other than a min of 4mm and sized based on the largest current conductor as defined in AS/NZS 3000.
The bonding conductor is not a “live” conductor and merely for sensing and earth fault. In fact it would still function perfectly well if it was uninsulated (as is the requirement in the US).
It is industry best practice to run the bonding conductor along with the PV array cables to reduce loop area within the array (which can increase the chances of induced voltages).”
End of quote from Glen
Cheers Peter
Glen is the Smart Energy Councils rep on EL-042, EL-005 and NT-001 is comments in an email to me are:
“There is nothing specific about the type of earth conductor used for equip bonding other than a min of 4mm and sized based on the largest current conductor as defined in AS/NZS 3000.
The bonding conductor is not a “live” conductor and merely for sensing and earth fault. In fact it would still function perfectly well if it was uninsulated (as is the requirement in the US).
It is industry best practice to run the bonding conductor along with the PV array cables to reduce loop area within the array (which can increase the chances of induced voltages).”
End of quote from Glen
Cheers Peter
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