Hi All,
My question is posed to those that may have insight into the reason for this amendment.
Is the change in amendment 2 of AS/NZS 3000-2018 now stipulating a 600mm clearance is required around the open door (i.e. in any position) of a domestic switchboard an oversight or an intentional change?
Background to the question: (sorry for using earlier Australian standards as references)
Since a change was introduced in the 1986 version of AS 3000 (1981 version was different) there has not been a requirement to provide a 600mm clearance around the open door of a domestic switchboard (as these generally don’t have doors in excess of an old 900mm-length dimension rule) Clause 2.21.2.1 from the 1986 and 1991 versions which is sort of carried through via clause 2.9.10 from the combined AS/NZS 3000 fit for purpose 2000 version.
Confusion came with the introduction of the 2007 version, when it combined the access and emergency exit facilities clauses.
Within the 2007 and 2018 versions, essentially it has been an interpretation as to which statements are for access and which were for emergency exits. While the reintroduction the of the 1 meter access (600mm domestic) requirement from the face of the enclosure is beneficial, the requirement for a 600mm clearance around the open door (i.e. in any position), apparently has been a little grey as to whether this was for access or an emergency exit facility. Due to previous mentioned standards, I’ve always stated this 600 mm clearance was to enable a safe emergency exit thus the exemption at the bottom of the clause ensured it wasn’t a requirement for a domestic switchboard. Additional reasoning for this justification was that the risk of personal injury due to an arc from these boards is very low thus not needing the same level of emergency exit facilities.
Reason for the question:
With the forever reducing land size, suitable switchboard locations are becoming difficult. When placed down the side of a premises, most times obtaining a 600mm to 1m clearance between the face of the switchboard and a fence/ retaining wall is achievable and provides sufficient access to safely work on the board. But if the entities where to enforce the new 600mm clearance from the open door most times the side wall of a premises would be deemed unsuitable.
Any information you can provide on this amendment would be appreciated and if it was an intentional change, do we have a recourse for requesting consultation with regards to changing?
Switchboard access changes due to AS/NZS 3000-2018 Amendment 2
Re: Switchboard access changes due to AS/NZS 3000-2018 Amendment 2
Sounds interesting. AlecK is probably all over this 
Re: Switchboard access changes due to AS/NZS 3000-2018 Amendment 2
Can only approach this in [NZ] context; as i have no experience or detailed knowledge of earlier [A] only Wiring Rules
Re: Switchboard access changes due to AS/NZS 3000-2018 Amendment 2
True in 2000 edition the "access' and 'egress' requirements were in different clauses.
And true in that edition there was a 0.6 m requirement "around switchboards' that was under the "emergency exit" heading.
Nothing about open doors etc.
Also nothing at all to explain what "adequate space' for access might be.
And yes these 2 clauses were combined in 2007 edition.
Whatever the thinking behind that combining was, we can't tell. But we have to accept that there were reasons.
The writers chose to amalgamate the clauses, which suggests they felt the issues of access & egress are related rather than being entirely separate.
At the same time a lot more detail was added; including the "around open doors" bit.
In currently-cited edition for NZ (2007+A1+A2); para 2 of 2.9.2.2 states that "sufficient access and egress facilities" has three parts:
(i) 0.6 m around the swbd, including around doors / racked-out gear
(ii) alternative exit path for larger / high-current swbds
(iii) adequate size of doorway.
The wording states that (ii) is primarily about egress, and (iii) is primarily about access; but provides no particular context for the 0.6 m dimension.
But that doesn't really matter. What matters is that we have to ensure it's provided.
In fact, since other aspects were specified as being related to "access" or to "egress'; and this one wasn't; we should consider: " why this difference?"
The logical inference is that they didn't want to specify 0.6 m as one or the other, but rather that it related to both.
To simply assume that the 0.6 m continued to apply only to "exit" is to ignore that changes are not made without good reason.
Having set that provision; the clause goes on to set further requirements WRT which way doors of switchroom open; and what sort of catch is allowed - all being under the overall heading of the clause : Accessibility and emergency exit.
Finally it provides an Exception; ie that the requirements for doors of switchrooms, and the requirements for emergency exit facilities "need not" apply for single domestic installations.
Some read this as meaning none of the clauses requirements apply; but since the clause covers both access and egress that's clearly not true.
Certainly the rules for switchroom doors don't apply to domestic - but then how often does a single domestic have a whole room for the swbd anyway?
Certainly the need for 2nd ("alternative") exit path doesn't apply to domestic - but again hard to see any of the trigger conditions existing in a domestic context.
Equally certainly; item (iii) is specifically "access"; so the Exception can't apply to that. True a domestic is unlikely to have a "room" but quite often has an "enclosure" (eg a cupboard).
Similarly para 1 - setting to general objectives - has three parts, and only one of them can be affected by the exception.
So we ALWAYS need to provide "access" that is 'not obstructed by the structure or contents of the building..." as per (a), and "adequate space" as per (b); even if the Exception can be read as removing (c)'s need for "sufficient exit facilities".
Bottom line is access requirements always apply. And I believe the 0.6 m rule is at least as much about access as it is about egress.
True it isn't explicitly stated one way or the other; while other requirements are clearly tied to either "access" or "egress".
But, as explained above, continuing to treat 0.6 m as being only an 'egress' requirement, and that therefore the Exception could apply, is simply not logical - in either country.
--------
Moving on to the new edition; and specifically the new item (i) requiring 1.0m around switchboards.
Noting that the other three items are still there, re-numbered as (ii), (iii), & (iv).
So the 600 mm from open door is not new; it's the same as the 2007 requirement.
Just that an additional requirement for 1.0 m from closed face has been added.
Basically (ii) still requires 0.6 around open doors; so no change to that aspect.
No change either to the wording of the exception (at east not for 2018 edition as published)
But new (i) requires 1.0 m around closed swbd - but not for domestic.
This is, in effect , an Exception to the new 1.0 m requirement and in later version (A2) is written as such.
It was put in not for external switchboards, but for internal switchboards - in recognition that passageways in domestic may be less than 1.0 m wide.
A2 also re-writes the entire clause; and both the 0.6 m and the 1.0 m requirements are clearly stated to be for "access"; not "egress".
Comparing "2018 +A1+A2" to "2000"; the clearances required around swbds have moved from being primarily about egress to now being primarily about access.
I think what the history of this clause shows is that the industry reps who make up the committee that writes the Standard are not stuck in old thinking; but are seeking continual improvement.
The changes made may not always be explained fully - or at all.
But the fact of any change being made requires readers to put aside old interpretations, and take the revised clauses on their own merit.
And true in that edition there was a 0.6 m requirement "around switchboards' that was under the "emergency exit" heading.
Nothing about open doors etc.
Also nothing at all to explain what "adequate space' for access might be.
And yes these 2 clauses were combined in 2007 edition.
Whatever the thinking behind that combining was, we can't tell. But we have to accept that there were reasons.
The writers chose to amalgamate the clauses, which suggests they felt the issues of access & egress are related rather than being entirely separate.
At the same time a lot more detail was added; including the "around open doors" bit.
In currently-cited edition for NZ (2007+A1+A2); para 2 of 2.9.2.2 states that "sufficient access and egress facilities" has three parts:
(i) 0.6 m around the swbd, including around doors / racked-out gear
(ii) alternative exit path for larger / high-current swbds
(iii) adequate size of doorway.
The wording states that (ii) is primarily about egress, and (iii) is primarily about access; but provides no particular context for the 0.6 m dimension.
But that doesn't really matter. What matters is that we have to ensure it's provided.
In fact, since other aspects were specified as being related to "access" or to "egress'; and this one wasn't; we should consider: " why this difference?"
The logical inference is that they didn't want to specify 0.6 m as one or the other, but rather that it related to both.
To simply assume that the 0.6 m continued to apply only to "exit" is to ignore that changes are not made without good reason.
Having set that provision; the clause goes on to set further requirements WRT which way doors of switchroom open; and what sort of catch is allowed - all being under the overall heading of the clause : Accessibility and emergency exit.
Finally it provides an Exception; ie that the requirements for doors of switchrooms, and the requirements for emergency exit facilities "need not" apply for single domestic installations.
Some read this as meaning none of the clauses requirements apply; but since the clause covers both access and egress that's clearly not true.
Certainly the rules for switchroom doors don't apply to domestic - but then how often does a single domestic have a whole room for the swbd anyway?
Certainly the need for 2nd ("alternative") exit path doesn't apply to domestic - but again hard to see any of the trigger conditions existing in a domestic context.
Equally certainly; item (iii) is specifically "access"; so the Exception can't apply to that. True a domestic is unlikely to have a "room" but quite often has an "enclosure" (eg a cupboard).
Similarly para 1 - setting to general objectives - has three parts, and only one of them can be affected by the exception.
So we ALWAYS need to provide "access" that is 'not obstructed by the structure or contents of the building..." as per (a), and "adequate space" as per (b); even if the Exception can be read as removing (c)'s need for "sufficient exit facilities".
Bottom line is access requirements always apply. And I believe the 0.6 m rule is at least as much about access as it is about egress.
True it isn't explicitly stated one way or the other; while other requirements are clearly tied to either "access" or "egress".
But, as explained above, continuing to treat 0.6 m as being only an 'egress' requirement, and that therefore the Exception could apply, is simply not logical - in either country.
--------
Moving on to the new edition; and specifically the new item (i) requiring 1.0m around switchboards.
Noting that the other three items are still there, re-numbered as (ii), (iii), & (iv).
So the 600 mm from open door is not new; it's the same as the 2007 requirement.
Just that an additional requirement for 1.0 m from closed face has been added.
Basically (ii) still requires 0.6 around open doors; so no change to that aspect.
No change either to the wording of the exception (at east not for 2018 edition as published)
But new (i) requires 1.0 m around closed swbd - but not for domestic.
This is, in effect , an Exception to the new 1.0 m requirement and in later version (A2) is written as such.
It was put in not for external switchboards, but for internal switchboards - in recognition that passageways in domestic may be less than 1.0 m wide.
A2 also re-writes the entire clause; and both the 0.6 m and the 1.0 m requirements are clearly stated to be for "access"; not "egress".
Comparing "2018 +A1+A2" to "2000"; the clearances required around swbds have moved from being primarily about egress to now being primarily about access.
I think what the history of this clause shows is that the industry reps who make up the committee that writes the Standard are not stuck in old thinking; but are seeking continual improvement.
The changes made may not always be explained fully - or at all.
But the fact of any change being made requires readers to put aside old interpretations, and take the revised clauses on their own merit.