Tesla Power-Wall. Is the installation of one of the units to a property that has existing solar HR/inspectable PEW?
My understanding is it’s not directly connected to the PV system, but connected to the switchboard (AC Coupled).
It’s a battery storage system not PV, is it mains parallel generation though?
TIA
Tesla Power-Wall
Re: Tesla Power-Wall
PV arrays are "high risK" if > ELV. This applies to the array only.
Mains parallel generation is always high risk; ie any situation with load connected to both mains and other (LV a.c.) source at same time.
If set up as an alternative supply, so load can only be supplied from one source or the other, then it isn't mains parallel;
but would still be 'high risk" if it affects mains.
The battery part of a system isn't any of these; but the inverter part may well be mains parallel.
Mains parallel generation is always high risk; ie any situation with load connected to both mains and other (LV a.c.) source at same time.
If set up as an alternative supply, so load can only be supplied from one source or the other, then it isn't mains parallel;
but would still be 'high risk" if it affects mains.
The battery part of a system isn't any of these; but the inverter part may well be mains parallel.
- Rating: 16.67%
Re: Tesla Power-Wall
Thanks. There doesn’t seem to be any specific standard for the battery system itself, only AS5139, which isn’t cited in the ESR.
I’m wondering whether it’s still expected that this standard should be adhered to. Our regulations seem seriously out of date!
I’m imagining trying to explain if something went wrong and you didn’t follow this standard, you’d likely be told it’s the only standard that’s available so it should’ve been used. So even if you were right, you’d still be wrong haha.
I’m wondering whether it’s still expected that this standard should be adhered to. Our regulations seem seriously out of date!
I’m imagining trying to explain if something went wrong and you didn’t follow this standard, you’d likely be told it’s the only standard that’s available so it should’ve been used. So even if you were right, you’d still be wrong haha.
Re: Tesla Power-Wall
I believe if you follow AS/NZS 5139:2019 (even though not cited) for battery installs you cant go wrong, at least you have followed the best practices available. The Electron magazine, Issue 103 (August 202) the "Board " recommends that electrical workers are able to reference the latest version of some standards that are not cited in the Regulations as they provide guidance on what is considered to be the "best practice" provided that it does not directly contradict a provision in a cited version.
I think AS/NZS 5139 is a new standard replacing AS4086.2-1997, so I assume as mentioned above using AS/NZS5139 should be ok but i could be wrong.
Cheers Peter
I think AS/NZS 5139 is a new standard replacing AS4086.2-1997, so I assume as mentioned above using AS/NZS5139 should be ok but i could be wrong.
Cheers Peter
- Rating: 16.67%
Re: Tesla Power-Wall
Yes, should always use latest edition available
UNLESS a particular provision conflicts with the cited documents - which isn't common, but does happen sometimes.
Note also that the battery is covered by '3000" same as the rest of the installation, and "3000" 2018 +A1 cites 5139 [clause 7.8.2.15]
As are many other Standards.
Such "secondary citations" (cited by another standard) always refer to latest edition;
and if the citing Standard is itself mandated by citation on ESRs, any secondary citation in it becomes legally binding also.
5139 is not replacing any previous Standard; and it's the only relevant guidance for today's systems using lithium type batteries; because the older '3011" series only covers lead-acid & nicad battery types.
UNLESS a particular provision conflicts with the cited documents - which isn't common, but does happen sometimes.
Note also that the battery is covered by '3000" same as the rest of the installation, and "3000" 2018 +A1 cites 5139 [clause 7.8.2.15]
As are many other Standards.
Such "secondary citations" (cited by another standard) always refer to latest edition;
and if the citing Standard is itself mandated by citation on ESRs, any secondary citation in it becomes legally binding also.
5139 is not replacing any previous Standard; and it's the only relevant guidance for today's systems using lithium type batteries; because the older '3011" series only covers lead-acid & nicad battery types.
- Rating: 16.67%
Re: Tesla Power-Wall
Hi Alec, I wonder why, when batteries are connected to a PV system >ELV and mains parallel generation that they are not regarded as High Risk Work as they form part of the PV system if DC coupled and even when AC coupled they are connected to communicate with the PV inverter for operating purposes.
Batteries are mentioned in AS/NZS 5033 and as discussed above, have there own standards and can be a source of high prospective fault currents and if not installed correctly can be a danger to persons and/or property, so hence my thinking.
Batteries are mentioned in AS/NZS 5033 and as discussed above, have there own standards and can be a source of high prospective fault currents and if not installed correctly can be a danger to persons and/or property, so hence my thinking.
Re: Tesla Power-Wall
Agree that there are significant fault current risks with even very small batteries, just because it's d.c.
Remember the risk categories aren't about how risky the work is; but rather how crucial the work is to the installation being safe to use.
There are things that arguably 'should' be classified as high risk PEW (eg replacing mains, or even a mains entry box).
And maybe some that currently are classed as high risk, but "shouldn't" be.
But that's a completely separate discussion from applying the rules as they have been written.
Currently even large battery banks are not classed as high risk work.
That said, nothing prohibits non-required third-party inspection.
To me the risk classifications for PEW on installations appear to be mostly drafted around LV a.c. from a grid type source of supply.
("3000" and companion Standards have mostly been written from a similar, limited, viewpoint.)
The overall system of certification, inspection, & connection uses connection to a source of supply as the primary demarcation.
You do the work; then you check it; then you certify it.
Only after all that has been don is it permitted to connect to supply.
For high risk PEW, there's the extra step of inspection; but again this happens before connection.
Which is entirely logical for LV a.c. (whether it's practicable in real life is another discussion).
And continues to work even if the source isn't a grid
Eg a genset, or treating an inverter as the source (which it never actually is, since an inverter is not a form of generation).
The logic is that there's (almost) no electrical risk during the construction / installation stages.
the electrical risk begins when the assembly of fittings is connected to a source of supply.
Which is why the ESC is the primary safety documentation.
However the logic doesn't hold up when the work is being done on something that actually IS a source of supply;
like batteries and PV arrays.
It's simply not possible to not be "connected to a source of supply" at any stage.
The logic also falls short for things like installing a new main earthing system 9or altering an existing one).
That's classed as high risk, because under the "MEN system of supply the MES is a fundamental part of ensuring installations are sufficiently safe for users.
But leaving it disconnected while you wait for an inspection makes no sense at all.
If you discover an existing installation has - for whatever reason - lost it's MES; surely better to get one connected and effective ASAP
but technically you have to leave it not "connected to a source of supply" until after inspection.
Remember the risk categories aren't about how risky the work is; but rather how crucial the work is to the installation being safe to use.
There are things that arguably 'should' be classified as high risk PEW (eg replacing mains, or even a mains entry box).
And maybe some that currently are classed as high risk, but "shouldn't" be.
But that's a completely separate discussion from applying the rules as they have been written.
Currently even large battery banks are not classed as high risk work.
That said, nothing prohibits non-required third-party inspection.
To me the risk classifications for PEW on installations appear to be mostly drafted around LV a.c. from a grid type source of supply.
("3000" and companion Standards have mostly been written from a similar, limited, viewpoint.)
The overall system of certification, inspection, & connection uses connection to a source of supply as the primary demarcation.
You do the work; then you check it; then you certify it.
Only after all that has been don is it permitted to connect to supply.
For high risk PEW, there's the extra step of inspection; but again this happens before connection.
Which is entirely logical for LV a.c. (whether it's practicable in real life is another discussion).
And continues to work even if the source isn't a grid
Eg a genset, or treating an inverter as the source (which it never actually is, since an inverter is not a form of generation).
The logic is that there's (almost) no electrical risk during the construction / installation stages.
the electrical risk begins when the assembly of fittings is connected to a source of supply.
Which is why the ESC is the primary safety documentation.
However the logic doesn't hold up when the work is being done on something that actually IS a source of supply;
like batteries and PV arrays.
It's simply not possible to not be "connected to a source of supply" at any stage.
The logic also falls short for things like installing a new main earthing system 9or altering an existing one).
That's classed as high risk, because under the "MEN system of supply the MES is a fundamental part of ensuring installations are sufficiently safe for users.
But leaving it disconnected while you wait for an inspection makes no sense at all.
If you discover an existing installation has - for whatever reason - lost it's MES; surely better to get one connected and effective ASAP
but technically you have to leave it not "connected to a source of supply" until after inspection.