Undergrounding of overhead lines

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Liam
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Undergrounding of overhead lines

Post by Liam »

A residential customer of mine in Auckland would like to underground existing overhead lines from street pole to house. (Both mains and communications)

I'm trying to figure out:

- Is a council building consent or any other permission required prior to starting works?

- What works would vector & chorus be responsible for and what works would I be responsible for installing?

- Is a electrical inspector required once works are complete? Who engages, vector or myself.


Cheers.
Liam.
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gregmcc
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Re: Undergrounding of overhead lines

Post by gregmcc »

I have done a lot of this kind of thing in Auckland, but more recently on the Waikato area,

Usually it is done entirely at the property owners expense.

The electrician generally runs the new wiring for chorus from the demarcation point to the nominated point outside the property line, Chorus will do the connection at the pole end at the home owners cost, they can do the whole phone line bit, but will charge an arm and a leg, for fiber throw a fiber duct in the trench (most wholesalers will supply the fiber duct for free), chorus will blow a new fiber in and do both ends.

Power, Vector will do from the nominated point outside the property line to their point of connection, arrange with them first as they may have a standard fee, they may want to put in a pillar in the ground to connect to, or they may allow for just a standard overhead to under ground (OHUG) conversion. Keep in mind they may decide that it may not be a standard install and it may become expensive very quickly.

Anything outside the property line will usually require council consent, Vector (or their contractor) will arrange the 'work access permit' from the council, and if need be traffic control (this is why it gets expensive very quickly)
You will need to engage an Inspector for the Installation portion of the work (the mains on the property owner side of the boundary), outside the boundary it becomes 'works' and does not need to be inspected.
Keep in mind as part of the inspection the Inspector will confirm that a main earth exists, old house generally used a handy metal water pipe, if this is the case a new main earth will be required - but a good idea is to talk to your regular inspector to see what they want you to do.
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Re: Undergrounding of overhead lines

Post by Liam »

Thank you, very helpful indeed.
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Re: Undergrounding of overhead lines

Post by AlecK »

Technically it's not the Inspector who must check that the installation has a main earthing system (MES). ESR 73A(1)(e)(iv) makes the person-about-to (re)connect the installation responsible for this. For undergrounding mains; that will be a linesman. However the person doing the job should be aware of the requirement, and have done any remedial work in good time - which means you should do your own check before commencing - quoting.

And just because the existing MES uses water pipe as electrode doesn't mean an upgrade is required. The requirement is that "there is a main earthing system". Nothing about it having to comply with modern requirements; so as long as it meets ESR 113 (ie complied when installed, is not electrically unsafe, and still complies with original requirements) it can remain and does not need to be replaced.
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Re: Undergrounding of overhead lines

Post by gregmcc »

Thanks Alec, you're right about "there is a main earthing system".

I've seen plenty of these water pipe main earths, usually a ratty bit of bare earth - around 2.5mm (but the old imperial size), Our policy when doing ohug's is if it is a water pipe style earth, to upgrade it.
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Re: Undergrounding of overhead lines

Post by AlecK »

True there's a good chance an old MES will not meet ESR 113; so we should always be prepared for the upgrade.
Also sometimes it may be that the alteration to the mains, eg shorter / larger conductors, may have an adverse effect on safety of the MES part of the installation; contrary to ESR 13.

But my main point was the distinction between the people involved; ie who is responsible for what.
The effect of which is that an Inspector can't properly issue fail RoI in basis of inadequate MES; 'cos all we Inspectors are responsible for is the high risk work itself.
And if it happens that one person undertakes more than one role; they need to be clear about which aspects they are doing under which "hat".
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Re: Undergrounding of overhead lines

Post by Liam »

gregmcc wrote:
Thu Apr 16, 2020 3:46 pm
I have done a lot of this kind of thing in Auckland, but more recently on the Waikato area,

Usually it is done entirely at the property owners expense.

The electrician generally runs the new wiring for chorus from the demarcation point to the nominated point outside the property line, Chorus will do the connection at the pole end at the home owners cost, they can do the whole phone line bit, but will charge an arm and a leg, for fiber throw a fiber duct in the trench (most wholesalers will supply the fiber duct for free), chorus will blow a new fiber in and do both ends.

Power, Vector will do from the nominated point outside the property line to their point of connection, arrange with them first as they may have a standard fee, they may want to put in a pillar in the ground to connect to, or they may allow for just a standard overhead to under ground (OHUG) conversion. Keep in mind they may decide that it may not be a standard install and it may become expensive very quickly.

Anything outside the property line will usually require council consent, Vector (or their contractor) will arrange the 'work access permit' from the council, and if need be traffic control (this is why it gets expensive very quickly)
You will need to engage an Inspector for the Installation portion of the work (the mains on the property owner side of the boundary), outside the boundary it becomes 'works' and does not need to be inspected.
Keep in mind as part of the inspection the Inspector will confirm that a main earth exists, old house generally used a handy metal water pipe, if this is the case a new main earth will be required - but a good idea is to talk to your regular inspector to see what they want you to do.
Greg, how do you go about getting fiber ducting free of charge from the wholesalers?
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Re: Undergrounding of overhead lines

Post by gregmcc »

Liam wrote:
Sun Apr 19, 2020 8:10 am


Greg, how do you go about getting fiber ducting free of charge from the wholesalers?
Walk in to your regular wholesaler and ask, they usually have them. I have got them from JA Russell, Ideal and Active, depending on demand they may have to order in. They should also have available the indoor fiber duct and the correct joiners for each type of duct.
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Re: Undergrounding of overhead lines

Post by Liam »

gregmcc wrote:
Sun Apr 19, 2020 8:19 am
Liam wrote:
Sun Apr 19, 2020 8:10 am


Greg, how do you go about getting fiber ducting free of charge from the wholesalers?
Walk in to your regular wholesaler and ask, they usually have them. I have got them from JA Russell, Ideal and Active, depending on demand they may have to order in. They should also have available the indoor fiber duct and the correct joiners for each type of duct.
Ok I'll ask my wholesaler, do you usually ask for the green ducting or the microduct when you are doing fiber ?
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Re: Undergrounding of overhead lines

Post by gregmcc »

The 500m drum of red microduct
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