First off, I know this standard is not cited but clause 2.10.2.2. has requirements for switchboards over 800A per phase or over 3m in length eg two emerg exits paths with an exception "where there is a clear space of at least 3m in front of the swb ....."
Many existing switchboard rooms don't meet these requirements, so what is the situation when a new swb is required in an existing building, I don't think ESR 59(3) (b) would apply as there could be different types of fuse protection to the original swb or other changes?
There is an exception after clause 2.10.2.2 (b) saying" this requirement need not apply when replacing an existing switchboard in the same location of the same or lesser rating", I assume this exception only applies to clause (b) though, or is applying to both clauses, a & b?
Just curious.
AS/NZS 3000:2018 clause 2.10.2.2.2
Re: AS/NZS 3000:2018 clause 2.10.2.2.2
Note that the Exception after (a) of 2.10.2.2.2 is inset to same degree as item (a), so it applies only to (a).
The Exception after (b) is not inset; so can be read applying to all of 2.10.2.2.2, ie both (a) for 2nd exit & (b) for doorway height.
However I believe the lack of indent is an editorial error; and it was intended to apply only to (b); else it should say "these requirements" (plural), not "this requirement" (singular).
And while it makes sense to not require an existing doorway to be enlarged; it doesn't make much sense to avoid the '2nd exit' requirement.
The whole point of 2.10.2.2.2 is to give installers some leverage over idiot architectural designers; who tend to ignore the fact that switchboards have to be got into the space somehow, and that people working in swbd rooms need adequate means of escape.
The Exception after (b) is not inset; so can be read applying to all of 2.10.2.2.2, ie both (a) for 2nd exit & (b) for doorway height.
However I believe the lack of indent is an editorial error; and it was intended to apply only to (b); else it should say "these requirements" (plural), not "this requirement" (singular).
And while it makes sense to not require an existing doorway to be enlarged; it doesn't make much sense to avoid the '2nd exit' requirement.
The whole point of 2.10.2.2.2 is to give installers some leverage over idiot architectural designers; who tend to ignore the fact that switchboards have to be got into the space somehow, and that people working in swbd rooms need adequate means of escape.
Re: AS/NZS 3000:2018 clause 2.10.2.2.2
Thanks Alec, the way I read it, as you say it only applies to (b) and not pural, so what about an existing situation when the swb rooms were not built that large an a building needs a new replacement swb, can you use ESR 59 93) (b)?
Re: AS/NZS 3000:2018 clause 2.10.2.2.2
A replacement of any fitting, or collection of fittings (such as a switchboard) is maintenance of the installation.
Refer ESR 6A; which defines maintenance or replacement of a fitting as low risk PEW.
Therefore ESR 59(3) applies, and all three options / pathways to compliance are available.
Including pathway (b): restore to /; maintain in "original condition".
"Original condition" is not a defined term, and allows flexibility. But it certainly does not restrict replacement to being only allowed using an exact copy of the original.
The intent of ESRs, as set out in 2010 original wording [ESR 60?; defining what PEW did not require a CoC], allowed for replacement using any fitting that was suitable for the circuit.
Note also ESR 113; which allows installations to remain in service as long as they complied when installed; still comply with original requirements, and are not electrically unsafe.
Now assume you choose pathway (a): maintenance such that the installation complies with "3000";
and clause 1.9.3.2 allows for repairs to be carried out using methods / fixtures / fittings that were acceptable when that part of the installation was originally installed (provided the fundamental principles are complied with - those fundamental principles being set our in clause 1.5).
So regardless of which of these pathways you choose, the work if replacement does not have to result in that part of the installation complying with latest requirements.
For your example of replacing a switchboard; clause 2.10.2.2.2 simply does not apply; and there is NO need to ad another exit, or increase the size of the door. Don't need to worry about the Exceptions, as they are Exceptions to a rule that doesn't apply anyway.
In fact the Exception after (b), that refers to a requirement not applying for replacement of same or lower rating; is simply repeating what 1.9.3.2 says. So the only real effect of this Exception is to allude to the fact that if the replacement swbd has a higher rating; it may have to be treated as an alteration to the installation; rather than as repair / maintenance. It's not automatically an alteration, but it could be.
The Exception doesn't specify which "rating" is being referred to; but the most obvious is load current.
That's the broad-brush over-view.
At a more detailed level, you can treat replacing a switchboard as equivalent to replacing a bunch of control / protective devices (emphasis mostly on protective, 'cos that's what makes it a swbd).
Assume the overcurrent devices were SERFs.
You can replace them with SERFs; there is no requirement to upgrade to eg mcbs.
Both pathways (a) & (b) permit SERFs as replacement for old SERFs.
But if you do use mcbs, it's still replacement of an overcurrent device. The device performs the same function (overcurrent protection).
Or you can use RCBOs, and you've added functionality. But it's still not an alteration; as you've still only replaced each device with another device that performs the same function. The new devices will have greater PFC rating. They will perform the overload function better (mcb or RCBO) or can add functionality (additional protection by RCD); but using them doesn't add load or do anything else to reduce safety, or functionality, or compliance with original requirements.
Which brings us to the more common case where the swbd being swapped-in is likely to have a higher load current rating, there may be more of them. But if the swbd is fed from the same mains / submains, with same protection; then the actual load current can't increase . So mut an alteration.
And if the extra devices haven't got any circuits attached, they don't affect actual load either.
However technically it can be argued that any increase in number of fittings is an alteration.
(though no-one in their right mind would suggest that just adding busbar / rack space increases the load.)
And clearly if you install RCCBs separate from the overcurrent devices, that's an alteration.
At least, you can't say it's replacement of a fitting that was there before; so ESR 6A makes if 'general" PEW.
So for purposes of ESRs, call some of the work replacement and some installation / alteration; and issue CoC.
For purposes of '3000"; rely on 1.9.3.2 and ignore any suggestion that the number or size of doors has to be changed.
Refer ESR 6A; which defines maintenance or replacement of a fitting as low risk PEW.
Therefore ESR 59(3) applies, and all three options / pathways to compliance are available.
Including pathway (b): restore to /; maintain in "original condition".
"Original condition" is not a defined term, and allows flexibility. But it certainly does not restrict replacement to being only allowed using an exact copy of the original.
The intent of ESRs, as set out in 2010 original wording [ESR 60?; defining what PEW did not require a CoC], allowed for replacement using any fitting that was suitable for the circuit.
Note also ESR 113; which allows installations to remain in service as long as they complied when installed; still comply with original requirements, and are not electrically unsafe.
Now assume you choose pathway (a): maintenance such that the installation complies with "3000";
and clause 1.9.3.2 allows for repairs to be carried out using methods / fixtures / fittings that were acceptable when that part of the installation was originally installed (provided the fundamental principles are complied with - those fundamental principles being set our in clause 1.5).
So regardless of which of these pathways you choose, the work if replacement does not have to result in that part of the installation complying with latest requirements.
For your example of replacing a switchboard; clause 2.10.2.2.2 simply does not apply; and there is NO need to ad another exit, or increase the size of the door. Don't need to worry about the Exceptions, as they are Exceptions to a rule that doesn't apply anyway.
In fact the Exception after (b), that refers to a requirement not applying for replacement of same or lower rating; is simply repeating what 1.9.3.2 says. So the only real effect of this Exception is to allude to the fact that if the replacement swbd has a higher rating; it may have to be treated as an alteration to the installation; rather than as repair / maintenance. It's not automatically an alteration, but it could be.
The Exception doesn't specify which "rating" is being referred to; but the most obvious is load current.
That's the broad-brush over-view.
At a more detailed level, you can treat replacing a switchboard as equivalent to replacing a bunch of control / protective devices (emphasis mostly on protective, 'cos that's what makes it a swbd).
Assume the overcurrent devices were SERFs.
You can replace them with SERFs; there is no requirement to upgrade to eg mcbs.
Both pathways (a) & (b) permit SERFs as replacement for old SERFs.
But if you do use mcbs, it's still replacement of an overcurrent device. The device performs the same function (overcurrent protection).
Or you can use RCBOs, and you've added functionality. But it's still not an alteration; as you've still only replaced each device with another device that performs the same function. The new devices will have greater PFC rating. They will perform the overload function better (mcb or RCBO) or can add functionality (additional protection by RCD); but using them doesn't add load or do anything else to reduce safety, or functionality, or compliance with original requirements.
Which brings us to the more common case where the swbd being swapped-in is likely to have a higher load current rating, there may be more of them. But if the swbd is fed from the same mains / submains, with same protection; then the actual load current can't increase . So mut an alteration.
And if the extra devices haven't got any circuits attached, they don't affect actual load either.
However technically it can be argued that any increase in number of fittings is an alteration.
(though no-one in their right mind would suggest that just adding busbar / rack space increases the load.)
And clearly if you install RCCBs separate from the overcurrent devices, that's an alteration.
At least, you can't say it's replacement of a fitting that was there before; so ESR 6A makes if 'general" PEW.
So for purposes of ESRs, call some of the work replacement and some installation / alteration; and issue CoC.
For purposes of '3000"; rely on 1.9.3.2 and ignore any suggestion that the number or size of doors has to be changed.
Re: AS/NZS 3000:2018 clause 2.10.2.2.2
Thanks again Alec!
If only the exceptions at the end of the clause 10.2.2.2 was written as a plural, it would be a lot clearer.
I was only browsing 3000:2018 and saw this clause hence the question, your reply is perfect.
If only the exceptions at the end of the clause 10.2.2.2 was written as a plural, it would be a lot clearer.
I was only browsing 3000:2018 and saw this clause hence the question, your reply is perfect.