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Posted By Topic: Multi ICPs.

Craig
May 17 2012 23:27

Hi all.

1 building.

3 flats.


3 sets of meters.

1 MEN poing ( obversly at the metering point ).

Is each install a \"seperate\" install , needing its own MEN link , and driven earth , OR is is the flats ment to be sub boards , unlinked.?

Craig
   

pluto
May 18 2012 07:47

One Master switchboard with MEN link which is also the main switchboard, 3 revenue meters (1 for each flat) which may increase if 2 or more tariffs per flat, but some smart meters are able to cater for more than 1 tariff in a common meter.

One distribution switchboard (NO MEN link) in each flat supplied from the master switchboard. The sub main may require multiple active cords to cater for 2 or more tariffs in each flat. Distribution switchboard inside each flat.
   

Brian H
May 18 2012 09:26

So one Electrode only required for MEN Board.1.8 Metre in Ground.Unless Earth Loop Impedence requires more Earthing?
   

carl
May 18 2012 13:47

So what is the deal with the rcd\'s to subcircuits in this instance?
   

AlecK
May 18 2012 14:24

One MEN = one installation.

Follows from rule that each installation shall have an MEN point at its MSB.

so only one MEC & electrode req\'d... regardless of EFLI or anyhting else.

And \"max-3-subcicuits\" rule applies \'cos it;\'s residential. Could get away with not splitting acroos min 2 RCDs per flat if no more than 3 subcircuit each. But not good practice. Always a good idea to split lighting across 2 subcircuits, even for small sections of installations. This meets requirement to \"minimise inconvenience\" in the event of a fault; which is stated in 1. 6.1(e) and repeated using different words in 2.2.1(c)
   

craig
May 20 2012 12:36

Hi all again what if the metering point is a standard house and it allready supplys a swbd in that house and say u want to split garage into sep metering.

you would run new cable from meterbox and thn fit a men board in the garage? but then there are technicly 2mens in the same building?


or would u have to convert the meterbox into the men point and have house and garage as unlunked switchboards? or do u run extra wire to the existing swbd in house and run garage from that rate?

cheers in advance
   

pluto
May 20 2012 15:42

craig May 20 2012 12:36
Your comment
Hi all again what if the metering point is a standard house and it already supplies a swbd in that house and say u want to split garage into sep metering.
You would run new cable from meter box and then fit a men board in the garage? but then there are technically 2 MENs in the same building?

My comment
Your knowledge of the MEN system of supply is not correct. In the Wiring rules the provisions the garage switchboard is using the outbuilding provision clause 5.5.3.1 of as/nzs 3000

However the outbuilding must meet all the requirements for out-building definition in clause 1.4.69 before this system of supply can be used.

If you want a circuit diagram use fig 5.1 while there is no revenue meters shown they would be immediately downstream of the main switch on the main switchboard, 1 for the garage (out building) protective device and the 2nd meter would directly supply all other protective devices.

The MEN connection in the outbuilding is NOT the same a MEN link in a outbuilding switchboard nor is the earth conductor a main earthing conductor as it required for a main switchboard, so there is only 1 MEN connnection for the whole installation.
   

pluto
May 20 2012 15:48

A point of calcification on the last para, it should read

The MEN connection in the outbuilding is NOT the same a MEN link in a MAIN SWITCHBOARD nor is the earth conductor a main earthing conductor as it required for a main switchboard, so there is only 1 MEN connection for the whole installation.
   

Craig
May 20 2012 21:02

So what you are saying pluto is that you would run the garage supply directly from the main switchboard , as you would a submain , but you would have this on a seperate meter in the meterbox.

That means that if the house Main switch was turned off then the other icp is switchd off also?


Also would the power authorities accept this? i know or one down here would not.

We have to bring supply into a locked box beside the meterbox , split out to the two mains ,

one for house and one for garage , but doin it this way you are \"staring\" out from the meters , with the mains , meaning BOTH boards have a main earth and an MEN link attached.

Basicly 2 sep installations , but the buildings a in fact one building???


I can see what you are saying in an ideal would the other ICP would be in fact just another meter in the main board and feed from that , but down here the power auth will not allow. Each must have its own mains , swbd the lot.


Thorghts?

Craig.
   

pluto
May 20 2012 22:45

Craig May 20 2012 21:02
Your comment
So what you are saying pluto is that you would run the garage supply directly from the main switchboard , as you would a submain , but you would have this on a seperate meter in the meter box.

That means that if the house Main switch was turned off then the other icp is switched off also?


Also would the power authorities accept this? i know or one down here would not.

We have to bring supply into a locked box beside the meter box , split out to the two mains ,one for house and one for garage , but doing it this way you are \"staring\" out from the meters , with the mains , meaning BOTH boards have a main earth and an MEN link attached. Basicly 2 sep installations , but the buildings a in fact one building???

My comment
what is wrong with a master switchboard, 2 revenue meters one master main switch and one MEN point ON the master board. All other switchboards are distribution switchboards with NO Men link excepting the switchboard installed to out-building requirements. This only needs one additional main switch and some minor rearrangement of the incoming mains cable connections.