AS/NZS 3000:2007 - 3.9.4.4 (a)

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Slovett
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AS/NZS 3000:2007 - 3.9.4.4 (a)

Post by Slovett »

I've come across some 'un-tradesman like' wiring in a new house that I'm pre-wiring.

The Solar installers have installed their PV Panels and have run 2 DC Strings (which are also hanging out unterminated through a flush box LIVE - 270VDC on each String, but thats a seperate issue) in a HD-T Solar Flexi Conduit from the roof penetration to their inverter Location by fixing (with saddles) to the UnderSide of the Roof Purlin (less than 50mm from the face of the supporting member to which the roofing material is attached). Which then triggers Clause 3.9.4.4.

So my question is - Does HD flexi Conduit satisfy (a)? I feel it doesn't. In my opinion a Roofing screw would have no problem screwing straight through an HD conduit thats fixed into place. Particularly if they decided to use longer screws as they usually seem to do when re-roofing. (b) Doesn't come into play as its a non conductive PVC and I doubt they have an internal Earthed screen within the Conduit. (c) won't help because the cables are straight from the Array and won't (as far as I know) have 30mA RCD protection

I'd be keen to see what everyone thinks

Thanks
PeteRig
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Re: AS/NZS 3000:2007 - 3.9.4.4 (a)

Post by PeteRig »

Just adding to what you have asked, in the draft 5033:2021 if goes through unchanged the DC cabling will not be able to within 600mm of a ceiling, flat roof situation cabling has to be within 1m of external walls, the requirements come with good diagrams to show what is required. One of the reasons for this requirement is if there was a fire in the building the fire fighters at times could rip the ceilings down with their hooks or whatever to gain access to the roof space so hence could hook any cabling (in this case the DC).
The draft standard is a good read, not sure where it is up to now, but I am sure the public comments have closed and i think it will be for NZ as well.
JamieP
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Re: AS/NZS 3000:2007 - 3.9.4.4 (a)

Post by JamieP »

Flexible HD conduit is not suitable in my opinion

Look to the un-cited 2018 version as they have specified a bit deeper into what's sufficient and what's not and clearly done this for clarification. To meet A the mech protection needs to be enough to prevent damage, B may not stop damage but is earthed to permit automatic disconnection of supply before someone can make contact and C simply protects a person who does make contact

2018 calls for a minimum of WSX3

Screenshot of WSX3 examples from 2018
Screenshot_20211112-075557_Google PDF Viewer.jpg
AlecK
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Re: AS/NZS 3000:2007 - 3.9.4.4 (a)

Post by AlecK »

Not just un-tradesman-like; it's non-compliant.
Slovett
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Re: AS/NZS 3000:2007 - 3.9.4.4 (a)

Post by Slovett »

Thanks again guys - yes 'Un-trademan like' was definitely an understatement.
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