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Posted By Topic: Installation & works boundary?

May 09 2018 18:57

I’m just trying to get a little more clarity around where the boundary between works and installation lies? Does the following statement sound reasonable (in most circumstances)?

‘Mains’ and ‘Mains Work’ are only terms that can be used when referring to an ‘installation’.

The boundary of an ‘installation’ is limited to the boundary of its property.

Therefore, whatever fittings and cabling that lie outside of the property must be ‘works’, and are exempt from inspection as ‘mains work’?

I understand there would be times this may not apply, such as when the network connection point may actually be on a property. But just trying to get a bit of a basic idea.


May 09 2018 20:28

The definition of "installation" is in the Act; and the installation commences at the "Point of Supply", which is also defined in the Act - and may be in any of several places.
For a typical o/h or u/g supply with supply fuse on a network's pole / pillar / pit, the POS will generally be where the mains conductors cross the boundary. They're still "mains" conductors between this point & the POS, even though this section is not part of the installation.
For cases where the supply fuse is within the structure, eg at MSB or external meterbox, the POS will generally be at load terminal(s) of supply fuse(s) & the equivalent N connection. In this case the "mains" commence at POS, and the cables from network to supply fuse are not "mains" even though they are (at least partly) within the structure / property that contains the installation.


May 09 2018 21:19

Oh yep. Thanks. I think I read in one of your other comments. Connection to a network fuse on a property would be high risk, as it's within the installation, and connection to a network fuse outside of the property would be considered 'works'. I'm just trying to work out if the connection is outside the property boundary it needs inspecting? It just seems a bit of a grey area. Cheers

May 10 2018 08:08

It also pays to check with the distribution company. Sometimes there are agreements in place for altering the point of supply (clause d). Also be aware some networks will retain ownership of HV assets (and would need an easement to do so if installed post 1/1/1993) where as others (if supplying 1 customer - not just 1 ICP) do not and the HV line may be part of the installation (and thus HV mains).

But for most urban installations it is where the exclusive mains crosses the boundary.

Several things to be aware of.

1) Private individuals do not own assets in the road reserve without specific agreement of the road controlling authority (RCA). Usually this is the council, or NZTA for highways.

2) Installations must be protected by a fuse (ESR 32). If there is no fuse between the lines (works) and the installation - its still works (or they are committing an offence). This is relevant when service mains are tapped hard on to the network line and the protection comes later (maybe at the main switch). This rule (if I am reading it right?) says its works until the main switch as I understand it.


May 10 2018 09:48

ESR 32? requires the network to provide short circuit & fault protection for "mains".
Note: they don't have to provide overload protection; that's our job.
Since the mains starts at PoS the required protection must either be at PoS (eg where supply fuse is within meterbox / MSB) or upstream of it (eg on/in pole / pillar / pit outside property boundary).
The protection need not be "exclusive fittings", could perhaps be the HV fuses upstream of the transformer. But generally there will be "exclusive fittings" supply fuse(s) , and often they will/ can provide overload protection so we don't have to. They don't do this to be nice; they do it to prevwent consumers taking more than their contracted supply capacity.
But we ALWAYS need to ask the question: what form(s) of protection are going to be provided, using what type of device(s)?

May 10 2018 10:35

Thanks for the feedback. It’s been most helpful. My initial statement seems a bit too basic, as there are often many variables to consider. I’ll have to look at ECP32, it’s not one I’m very familiar with.

I noticed the ESR does in fact mention ‘mains work on an installation’ rather than just ‘mains work’ as being high risk.

So I’m guessing in most circumstances when the network connection is made outside the property boundary, or outside of the installation boundary. It’s being done as ‘works’.

I’m just trying to establish whether an inspector falls into the category of inspecting his own work, when making this connection, as this generally seems to be an inspectors task?

May 10 2018 10:41

Making the final connection is uncatgorized risk work - even if made inside the installation. ESR73A 1d says the person doing the connection must either inspect or sight an RoI form an inspector. The idea being that the inspector, once they have completed the inspection, can make that final connection.

Re ESR 32 (not ECP). Yes agree Alek. The reason I raised it as some network companies have said "if its on your land and supplies just you - its yours". However if they havent got a fuse (or similar) at the point of exclusivity (my own term) then it cant be installation at boundary cross - it must remain works up until the first fuse (or similar).

Ive seen this a few times where service lines (both HV and LV) are tapped hard on and a fuse exists well within the property (side of the house). Installation starts after the fuse in this case. That is what I was getting at.

May 10 2018 12:05

Yes there can be an agreement for a non-standard PoS. But would think it would have to be in writing - not just a network trying to avoid responsibility for maintenance by saying 'that line / those poles are your problem now". Though will need to re-read the relevant bit of the Act.

The mere presence / absence / location of a service fuse doesn't necessarily tell us much. Bottom line is we need to KNOW, not just guess, where the PoS is, as that governs a lot of stuff including not only certification but who (class of PL / authority to work on network assests) can do the work.