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Posted By Topic: New shed feed from meter board

Oct 18 2017 09:48

Just checking of got this idea right guys. I do little of this new connection stuff so bear with me.

Parents have built a new shed on their farm. House has its own meter and is fed from a pole on their property 80m or so away. At the bottom of this pole however, is another meter. This is fed by a bit of 6mm then back up to continue on down to a pump shed and woolshed down the farm. Both very small loads, and protected by a 20A Hrc after the meter.

The new shed is just going to have a few led lights and socket outlets (2 circuits). Am I right in thinking I can put say a 32A mcb in meter board after the meter from the Hrc fuse feed side, run an underground ducted cable with phase and neutral to the new shed and drive an earth peg there? I\'ll have to re-crimp the neutrals under one lug I assume.

Thanks for your help. Hate to get the inspector out and look like an idiot having missed something crucial!

Oct 18 2017 11:14

Depends whether this is one installation or two. Which in turn depends on location of POS9s). But most likely one installation.

In which case IF the enclosure at bottom of pole is set up correctly as main switchboard (c/w main switch, MEN, MEC & earth electrode) and each outgoing circuit is set up correctly as a submain with appropriate overcurrent protection; then you can probably add another submain for the new shed provided the additional load doesn\'t cause any problems (eg volt drop) for the existing stuff.

But if instead it\'s the typical non-compliant lash-up; you\'ll have to bring it up to current Rules first.

The fact that one meter is at house and one at pole doesn\'t necessarily matter; but suggests that when installed the two may have been considered to be separate installations by the then Supply Authority (Power Board or similar). Worth checking the power bill(s); separate accounts for different ICPs indicates they are probably separate installations. As would the absence of any MEN point at the pole. But what you really need is a statement from the network as to where the point(s) of supply is / are.

If they are separate installations, you may be able to add the new bit to one or the other, or may have to (or want to) amalgamate them. How to do that depends on what exactly is there.

Bottom line is that network practices that used to be common sometimes don\'t comply with current Wiring Rules. They can usually continue in service under ESR 113; but any alteration may trigger a requirement to upgrade.

So forget the small risk of looking silly; talk to a local inspector asap. They should be able to offer advice - and often the advice will be worth much more than you pay for it.

Oct 18 2017 14:37

Thanks for your help. I had a feeling it wouldn\'t be so simple. I\'m guessing the farm side of things is on a seperate bill to the house and the meter board at the bottom of the pole, being without a MEN point or any earth for that matter, will not comply. There is actually another dwelling and shed with 3 phase supply nearer the start of the property. Talking to an inspector and figuring out what is required will be best.