I would like input from electricians,
to say wether or not that this legal.
I recently inspected a property, that was
recently built, it had 3phase Mains@ 6mm2
although the range was fed w/ a 2.5mm2,
2C+E,the Hot Water was fed through a
1.0mm2(pilot wire), am I wrong in saying
that this installation, did not comply with
NZS/AS 3000?.
Your input please..

[This message has been edited by Trumpy (edited 09-04-2002).]

Although I'm not familiar with your codes, this sounds like a nightmare.In Austria 6 sq mm is already required for a small appartment, and the hot water fed with 1 mm2 cable definitely isn't kosher. How many watts has that thing?

That sounds as though those cables are way undersized.

Most immersion heaters here are 3kW and fed with 2.5mm cable (12.5A load). What loading is the electric range and what size is the OCPD? 2.5 would generally only be suitable for the "Baby Belling" type portable units here. Most ranges are fed with a 30A fuse or C/B and 6mm cable.

Here are the cable ratings for PVC-sheathed multicore as per 1992 IEE Wiring Regs.:



(Sorry it isn't clearer; the table is printed on a gray background.)

As some folk here already know, personally I feel that some of the ratings listed these days are much too high anyway.



[This message has been edited by pauluk (edited 08-11-2002).]

Hi there Trumpy

"it had 3phase Mains@ 6mm2"

If the Mains cable qualifys after volt drop and current carrying etc..type NS or XLPE, is taken into account then it maybe ok..

"the range was fed w/ a 2.5mm2"2C+E

If it just a wall mounted oven then this is practiced alot, if it has a built in cook top then is a bad thing no way 2.5 is good to 30 amps.

"the Hot Water was fed through a 1.0mm2(pilot wire}"

Not sure what you mean about the pilot wire

"I recently inspected a property"

did you sign it off ?

Thanks for your input guys,
With re-inspection, the following was
found:
The Range was spread over Two Phases+
neutral, No Earth Conductor.
Hot Water Cylinder was wired with 1.5mm,
solid core( we have not used this type of
wire for YEARS).
Also the H/W was wired to a D Curve (Motor
Rated) MCB,20A.
Also on this installation, it turns out
that the Builder, because all of the
Electricians, were too busy,thought that
he would wire the whole house himself.
It took us a week to actaully re-wire
this house, to bring it up to Regs standard.
I am an Aerial Technician, as well as an
Electrician, and it is only after people
move into these houses, that they cannot get any reception,that I find these other
"problems"," While you are here, can you
have a look at this".
I have put a complaint in to the Electrical
Workers Registration Board, over this one.
To bring this sort of work by un-registered
to light, by God, it needs it.

Re Old Appy's comments:
Installation was fed thru 6mm N/s 3C+
Screening, this was provided by an indepen-
dent contractor, up to the main switch-board.
The Range that I was actually speaking
about was, a free-standing type, these
appliances have a current loading of
30Amps, when supplied by a single phase
supply,(with all equipment turned on)
However,we size our breakers @ 32 Amperes,
and run the circuits for them in 6mm2,
Even spread over @ 2 phases, this would
require a 4mm2,3Core+Earth cable.
With respect to the "Pilot Wire", mate,
the pilot wire, is the wire that feeds the
Main Switch-board, from the Ripple Supply
side of the Metering system, this feeds a
circuit-breaker,normally 20 Amperes.
It is normally run in 2.5mm2 or 4mm2,
depending on the size of the house,
But, it always has at least 4 conductors
in the Pilot Cable, for future requirements.

Re Old Appy's comments:
Installation was fed thru 6mm N/s 3C+
Screening, this was provided by an indepen-
dent contractor, up to the main switch-board.
The Range that I was actually speaking
about was, a free-standing type, these
appliances have a current loading of
30Amps, when supplied by a single phase
supply,(with all equipment turned on)
However,we size our breakers @ 32 Amperes,
and run the circuits for them in 6mm2,
Even spread over @ 2 phases, this would
require a 4mm2,3Core+Earth cable.
With respect to the "Pilot Wire", mate,
the pilot wire, is the wire that feeds the
Main Switch-board, from the Ripple Supply
side of the Metering system, this feeds a
circuit-breaker,normally 20 Amperes.
It is normally run in 2.5mm2 or 4mm2,
depending on the size of the house,
But, it always has at least 4 conductors
in the Pilot Cable, for future requirements.
With respect to Certification of this
Losers idea of an installation, it was
not certified, until such time, as I was
satisfied, that all of the work was safe.
It took the work of myself and three(3)
apprentices, to correct.
It's all fixed up now guys.

you have to wonder how these installation get connected in the first place?

"With respect to the "Pilot Wire", mate,
the pilot wire, is the wire that feeds the
Main Switch-board, from the Ripple Supply
side of the Metering system, this feeds a
circuit-breaker,normally 20 Amperes.
It is normally run in 2.5mm2 or 4mm2"

Thanks for clearing that up for me, mate

I'm lost here. Is this some strange system peculiar to NZ?

its used to interupt the supply to the hot water storage heaters at peak demand times sometimes with a Hz sensitive relay or a "pilot wire' run with the network supply and into the house.

as i know it - cheers

Thanks -- Interesting arrangement.

The closest I've seen to that is the system used in some French houses which automatically cuts-out heating loads when more power is needed on regular portable appliance outlets. It's used where service is of limited capacity.