Residential Wiring Faq?

[PJ]

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max number
of gpos per circuit, fuse sizes etc?

Thanks

Paul

 

[Unbeliever]

"PJ" <a@b.c> wrote in message
news:6pY8b.101479$bo1.40660@news-server.bigpond.net.au...

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max
number
of gpos per circuit, fuse sizes etc?

The definitive document is AS/NZS 3000:2000 available from Standards
Australia for about $80 for non-members. Some inkling can be gained from
the faq at http://www.wiringrules.com.au/ though this is better read in
conjunction with AS3000:2000. Both are designed for licensed electricians.

Cheers,
Alf
alfkatz@remove.the.obvious.ieee.org
www.micromagic.net.au

 

[Phil Allison]

"PJ" <a@b.c> wrote in message
news:6pY8b.101479$bo1.40660@news-server.bigpond.net.au...

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max
number
of gpos per circuit, fuse sizes etc?

** From my experience dealing with sparkies, you can have up to 20
switched outlets on one 15 amp domestic power circuit - double outlets
count as two. Nowadays, thermal/magnetic breakers are used in preference
to wire fuses - 15 amp ones ( = 3600 watts of load ) for a domestic GPO
circuit, 8 amp ones ( = 1920 watts of lights) for a lighting circuit.

The maximum cable length depends on the acceptable voltage drop at
full load, with 2.5 square mm wire there is about 0.23 volts loss per metre
at 15 amps - so I guess about 50 metres ( 11.5 volts loss) is a sensible
limit.


............ Phil

 

[KLR]

On Sun, 14 Sep 2003 11:36:34 GMT, "PJ" <a@b.c> wrote:

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max number
of gpos per circuit, fuse sizes etc?

Thanks

Paul

As I recall (QLD) there can be 10 power points on the first circuit -

and 20 on each additional one. (a double counts as 2)

Light fittings should be pretty easy - as they are fixtures each of a
known wattage you should ensure that when all of them are switched on
- the total circuit current doesnt exceed 8 amps/10 amps (depending
on lighting fuse rating)

Haymans locally do stock a book of the standards and regulations for
wiring in Australia. ( I have seen it in the display case there)
Don't know the cost - ring them and enquire.

Failing this - get an electrician out to give a quote - or specify
what you want done - in some detail in order to get a more accurate
picture. Most of the charges involved will be based on the time the
electrician takes to perform the work and not so much in the materials
(unless you are buying fancy or unusual high priced fittings). IE: a
power point installed in a room where there isn't any wiring nearby is
going to cost more than installing one next to an existing one or on
the other side of the same wall to an existing one

If you want really large numbers of power points - air cond, pool
filters, electric stove and hot water etc - you may have to factor in
the cost of extra phases being added by the electricity authority.
Typcially an upgrade to 3 phase from single is $800. (as I was quoted
in January) There may possibly be extra fees for extra meters or
meter reading charges in addition to this ?

 

[Shannell]

$800 wow thats cheap??? I was quoted $15000 by AGL, and the guy quoting
implied that was normal...

"KLR" <kreed@bigpond.net.au> wrote in message
news:7go8mvo6c8knh1j5u55nic46arnvngojfh@4ax.com...

On Sun, 14 Sep 2003 11:36:34 GMT, "PJ" <a@b.c> wrote:

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max
number
of gpos per circuit, fuse sizes etc?

Thanks

Paul

As I recall (QLD) there can be 10 power points on the first circuit -
and 20 on each additional one. (a double counts as 2)

Light fittings should be pretty easy - as they are fixtures each of a
known wattage you should ensure that when all of them are switched on
- the total circuit current doesnt exceed 8 amps/10 amps (depending
on lighting fuse rating)

Haymans locally do stock a book of the standards and regulations for
wiring in Australia. ( I have seen it in the display case there)
Don't know the cost - ring them and enquire.

Failing this - get an electrician out to give a quote - or specify
what you want done - in some detail in order to get a more accurate
picture. Most of the charges involved will be based on the time the
electrician takes to perform the work and not so much in the materials
(unless you are buying fancy or unusual high priced fittings). IE: a
power point installed in a room where there isn't any wiring nearby is
going to cost more than installing one next to an existing one or on
the other side of the same wall to an existing one

If you want really large numbers of power points - air cond, pool
filters, electric stove and hot water etc - you may have to factor in
the cost of extra phases being added by the electricity authority.
Typcially an upgrade to 3 phase from single is $800. (as I was quoted
in January) There may possibly be extra fees for extra meters or
meter reading charges in addition to this ?

 

[KLR]

On Sun, 14 Sep 2003 23:46:36 +0930, "Shannell" <sjs@ihug.com.au>
wrote:

$800 wow thats cheap??? I was quoted $15000 by AGL, and the guy quoting
implied that was normal...

This was to supply and fit a new meterbox large enough for the 2 extra

meters - to connect to the underground power box about 7 metres away
at the footpath - replace the main switch, redistribute the circuits
etc. etc. This was in a brick veneer residence in suburbia that was
about 10 years old and therefore had modern electrical gear installed.

Costs for the 3 phase socket(s) and the wiring and labour was extra
(and varied depending on where it was to go and how much labour was
involved). In this case it was proposed to put the socket in a rear
work shed behind the house that would have involved underground power
work and running the 4 mm squared cable through the roof from one end
of the house to the other. In other words - a shit job

The proposed tenant was to pay for it not me - but I was the one that
got the quote from the electrician when he was there giving the place
an electrical safety check. The 3 phase work didn't proceed so I
can't tell you the final actual cost.

"KLR" <kreed@bigpond.net.au> wrote in message
news:7go8mvo6c8knh1j5u55nic46arnvngojfh@4ax.com...
On Sun, 14 Sep 2003 11:36:34 GMT, "PJ" <a@b.c> wrote:

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max
number
of gpos per circuit, fuse sizes etc?

Thanks

Paul

As I recall (QLD) there can be 10 power points on the first circuit -
and 20 on each additional one. (a double counts as 2)

Light fittings should be pretty easy - as they are fixtures each of a
known wattage you should ensure that when all of them are switched on
- the total circuit current doesnt exceed 8 amps/10 amps (depending
on lighting fuse rating)

Haymans locally do stock a book of the standards and regulations for
wiring in Australia. ( I have seen it in the display case there)
Don't know the cost - ring them and enquire.

Failing this - get an electrician out to give a quote - or specify
what you want done - in some detail in order to get a more accurate
picture. Most of the charges involved will be based on the time the
electrician takes to perform the work and not so much in the materials
(unless you are buying fancy or unusual high priced fittings). IE: a
power point installed in a room where there isn't any wiring nearby is
going to cost more than installing one next to an existing one or on
the other side of the same wall to an existing one

If you want really large numbers of power points - air cond, pool
filters, electric stove and hot water etc - you may have to factor in
the cost of extra phases being added by the electricity authority.
Typcially an upgrade to 3 phase from single is $800. (as I was quoted
in January) There may possibly be extra fees for extra meters or
meter reading charges in addition to this ?

 

[Newsy]

"Shannell" <sjs@ihug.com.au> wrote in message
news:bk1t75$44k$1@lust.ihug.co.nz...

$800 wow thats cheap??? I was quoted $15000 by AGL, and the guy quoting
implied that was normal...

I had my house upgraded to 3 phase about 12 months ago - in addition to a 10
pair telephone cable and gas. The run was about 30 metres up the drive to
the house. Cost including the AGL work was about $6K for all services,
including upgraded meter box, new meters, ELCB's etc.

Rod

 

[John Crighton]

On Mon, 15 Sep 2003 08:54:40 +0930, "Newsy" <rlg000@hotmail.com>
wrote:

"Shannell" <sjs@ihug.com.au> wrote in message
news:bk1t75$44k$1@lust.ihug.co.nz...
$800 wow thats cheap??? I was quoted $15000 by AGL, and the guy quoting
implied that was normal...


I had my house upgraded to 3 phase about 12 months ago - in addition to a 10
pair telephone cable and gas. The run was about 30 metres up the drive to
the house. Cost including the AGL work was about $6K for all services,
including upgraded meter box, new meters, ELCB's etc.

Rod


Hello Rod,

that is a fantastic cost!
I want to get three phase power at my place, mainly in the shed. I
just can't understand the reluctance of the power companies
to just give it to me as a consumer. Apparantly running a lathe
with a three phase motor is not a good enough reason.

When my kid completed his electrical apprenticeship I wanted
him to fix me up with three phase power before he took off on
his world trip. Nope, he had to have a special licence, meaning
an additional tech course which he wasn't willing to do. I asked
an electrician acquaintance to do the job. he said he could fit
the meter, about 300 dollars, from Laurance and Hansen,
but he did not have the endorsement on his licence to
climb the street power pole and attach the wires. I am
amazed from an electronics point of view at how such
a simple job of adding a couple of extra wires between
the street and the house can be so frustrating.

I am kicking myself now. Years ago I had a neighbour
who was an electrician with the power company. I used
to do the odd bit of electrical work at my place and he
would check it, correct it if necessary and fix the paper
work when required. He used to blow his CB radio with
a dose of reverse polarity regularly and I used to repair it.
Dave, where are you. when I need you! heh heh heh...
Ah well, I will just wait and maybe meet an electrician
with all the necessary meter fitting and power pole climbing
licences who needs his telly or something fixed.

Frustrated,
John Crighton
Hornsby

 

PJ wrote:

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max number
of gpos per circuit, fuse sizes etc?

Thanks

Paul

A building inspection by the Archicentre (Vic) will give you a pretty comprehensive
idea of any potential problems, and they will suggest solutions. This can give you
an indication of further expense, eg, removal of asbestos, etc, apart from improving
or extending the electrical wiring. A further inspection by a qualified electrical
inspector should answer your question.

http://www.archicentre.com.au/html/home.html

--

David

 

[GM]

<dmmilne@ozemail.com.au> wrote in message
news:3F65185C.C5CE741A@ozemail.com.au...

PJ wrote:

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added
to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max
number
of gpos per circuit, fuse sizes etc?

Thanks

Paul

A building inspection by the Archicentre (Vic) will give you a pretty
comprehensive
idea of any potential problems, and they will suggest solutions. This can
give you
an indication of further expense, eg, removal of asbestos, etc, apart from
improving
or extending the electrical wiring. A further inspection by a qualified
electrical
inspector should answer your question.

http://www.archicentre.com.au/html/home.html

--

David

Hi all,
I'll throw my two cents in (I am a licensed electrician) - The
number of points on a power or light circuit in a domestic installation is
basically governed by the current rating of the conductor and the method
used to protect it. eg for power circuits, a minimum of 2.5mm2 conductor is
required. With a 20 amp HRC fuse or Circuit Breaker and at least two power
circuits, there is no limit to the number of points (providing the cable is
not derated in any way eg by insulation etc). Same goes for light circuits
eg 1.5mm2 protected by a 10amp HRC fuse or Circuit breaker there is no limit
to the number of points (you need to look at AS3000 for a definition of a
lighting point). As for rewirable fuses - I won't go into it but Phil is
basically correct, except a double GPO still counts as only one point. I can
see a huge argument erupting here about it being ridiculous to have an
unlimitednumber of GPO's on a power circuit, so obviously, a certain amount
of common sense would need to be applied.
Regards
Giles

 

On Sun, 14 Sep 2003 23:46:36 +0930, "Shannell" <sjs@ihug.com.au>
wrote:

$800 wow thats cheap??? I was quoted $15000 by AGL, and the guy quoting
implied that was normal...

That's probably also including a 3 phase tranfomer assuming you're a
rural customer.

 

[PJ]

The house has old-style wired fuses - do i understand correctly that if
these are changed to newer style circuit breakers, the maximum load for each
circuit is lower? Are the new circuit breakers much of an improvement over
the old wire fuses?

Thanks for your responses.

Hi all,
I'll throw my two cents in (I am a licensed electrician) - The
number of points on a power or light circuit in a domestic installation is
basically governed by the current rating of the conductor and the method
used to protect it. eg for power circuits, a minimum of 2.5mm2 conductor
is
required. With a 20 amp HRC fuse or Circuit Breaker and at least two power
circuits, there is no limit to the number of points (providing the cable
is
not derated in any way eg by insulation etc). Same goes for light circuits
eg 1.5mm2 protected by a 10amp HRC fuse or Circuit breaker there is no
limit
to the number of points (you need to look at AS3000 for a definition of a
lighting point). As for rewirable fuses - I won't go into it but Phil is
basically correct, except a double GPO still counts as only one point. I
can
see a huge argument erupting here about it being ridiculous to have an
unlimitednumber of GPO's on a power circuit, so obviously, a certain
amount
of common sense would need to be applied.
Regards
Giles

 

[James]

snip snip
fuses - I won't go into it but Phil is

basically correct, except a double GPO still counts as only one point. I can
see a huge argument erupting here about it being ridiculous to have an
unlimitednumber of GPO's on a power circuit, so obviously, a certain amount
of common sense would need to be applied.
Regards
Giles

That was my understanding of it as well though im an engineer not a
sparky. Basically I think you have to take into consideration of the
expected load of the appliances being plugged into the outlet, the
rules assume that someone has a brain somewhere along the line . If
the load was mobile phone charges only, you could have hundreds of
outlets or if it was RAC's, you might only have one outlet. If you
assume that the people who will use the electrical installation are
stupid and are likely to plug all sorts of stuff in the outlets, you
will be pretty close to being accurate in a lot of instances I have
seen so far

Your local supply authority may have some additional rules (and
sometimes relaxations) on AS3000. Here they have a few to do with max
demand and aircons - 100% of connected airconditioners commercial
buildings for instance. How come 3 phase power is such a hassle in
some places? Haven't known it to be an issue here unless its
unavailable in the street. Be handy if all houses had it actually.

well thats my 2 cents worth, have fun and try not to get too many
shocks

James

 

[Gavin]

"GM" <hathill2000@yahoo.com.au> wrote in message news:<3f652c9a@news.rivernet.com.au>...

dmmilne@ozemail.com.au> wrote in message
news:3F65185C.C5CE741A@ozemail.com.au...
PJ wrote:

I am looking at buying a house and would like to get an idea of how much
re-wiring will be required and how many gpos and lights could be added
to
the exisiting wiring. Is there anyone or any web site that details some
broad outlines for residential wiring e.g. maximum cable length, max
number
of gpos per circuit, fuse sizes etc?

Thanks

Paul

A building inspection by the Archicentre (Vic) will give you a pretty
comprehensive
idea of any potential problems, and they will suggest solutions. This can
give you
an indication of further expense, eg, removal of asbestos, etc, apart from
improving
or extending the electrical wiring. A further inspection by a qualified
electrical
inspector should answer your question.

http://www.archicentre.com.au/html/home.html

--

David

Hi all,
I'll throw my two cents in (I am a licensed electrician) - The
number of points on a power or light circuit in a domestic installation is
basically governed by the current rating of the conductor and the method
used to protect it. eg for power circuits, a minimum of 2.5mm2 conductor is
required. With a 20 amp HRC fuse or Circuit Breaker and at least two power
circuits, there is no limit to the number of points (providing the cable is
not derated in any way eg by insulation etc). Same goes for light circuits
eg 1.5mm2 protected by a 10amp HRC fuse or Circuit breaker there is no limit
to the number of points (you need to look at AS3000 for a definition of a
lighting point). As for rewirable fuses - I won't go into it but Phil is
basically correct, except a double GPO still counts as only one point. I can
see a huge argument erupting here about it being ridiculous to have an
unlimitednumber of GPO's on a power circuit, so obviously, a certain amount
of common sense would need to be applied.
Regards
Giles

Hi there
From the year 2000, the Wiring Rules have undergone some
major changes. One paticular change concerns the minimum size
conductor for a power circuit. ie, there is no longer a minimum size.
The pre 2000 Wiring Rules stated a minimum of 2.5mm2, but the AS/NZS
3000:2000 Wiring Rules appear to have no such requirment, provided the
cable is protected by the correct Circuit Breaker / Fuse, taking into
account all Derating Factors.
A double GPO used to count as one point for the purpose of
Number Of Points on the circuit, but TWO Points for the purpose of
calculating Maximum Demand. As Giles mentions, there is no limit to
the number of points (from 2000 onwards)but common sence must be
applied.
As far as a rewire is concerned, provided the wiring is
Plastic Insulated and in good condition, then a Rewire as such is not
required. Some additional circuits however would be wise. Also,
depending on the age of the house, does the lighting circuit have an
earth wire? Don't laugh, in the Fifties/Sixties it was not necessary.
It is now, as is an ELCB on every light circuit as well as every power
circuit (or the installation as a whole).
As for circuit breakers, Power 20A, Lighting 10A, Stove 25A
(over two phases)or 32A (single phase), Air Con, say 20A(three phase)
or 32A (single phase). Finally, do not become complascent when it
comes to voltage drop. While not generally an issue in a domestic
installation, equipment like Air Conditioners and Portable Air
Compressors can draw large currents on startup.

 

[Mark van der Eynden]

tutrades@cia.com.au (Gavin) wrote in message news:<eba6c144.0309150552.6ebd17ab@posting.google.com>...

"GM" <hathill2000@yahoo.com.au> wrote in message news:<3f652c9a@news.rivernet.com.au>...

Hi there
From the year 2000, the Wiring Rules have undergone some
major changes. One paticular change concerns the minimum size
conductor for a power circuit. ie, there is no longer a minimum size.
The pre 2000 Wiring Rules stated a minimum of 2.5mm2, but the AS/NZS
3000:2000 Wiring Rules appear to have no such requirment, provided the
cable is protected by the correct Circuit Breaker / Fuse, taking into
account all Derating Factors.
A double GPO used to count as one point for the purpose of
Number Of Points on the circuit, but TWO Points for the purpose of
calculating Maximum Demand. As Giles mentions, there is no limit to
the number of points (from 2000 onwards)but common sence must be
applied.

Is this to say that my new house, being built by 'Extremely El Cheapo

Homes', could use 1.5mm2 for wiring, have a 10A power fuse and string
it all out to 20 or so double GPOs? (maybe even placing wiring and
lighting of the same single fuse?)

Nothing like reverse bureaucracy to make your day

 

[David]

On Mon, 15 Sep 2003 16:36:36 -0700, Mark van der Eynden wrote:

tutrades@cia.com.au (Gavin) wrote in message news:<eba6c144.0309150552.6ebd17ab@posting.google.com>...
"GM" <hathill2000@yahoo.com.au> wrote in message news:<3f652c9a@news.rivernet.com.au>...

Hi there
From the year 2000, the Wiring Rules have undergone some
major changes. One paticular change concerns the minimum size
conductor for a power circuit. ie, there is no longer a minimum size.
The pre 2000 Wiring Rules stated a minimum of 2.5mm2, but the AS/NZS
3000:2000 Wiring Rules appear to have no such requirment, provided the
cable is protected by the correct Circuit Breaker / Fuse, taking into
account all Derating Factors.
A double GPO used to count as one point for the purpose of
Number Of Points on the circuit, but TWO Points for the purpose of
calculating Maximum Demand. As Giles mentions, there is no limit to
the number of points (from 2000 onwards)but common sence must be
applied.

Is this to say that my new house, being built by 'Extremely El Cheapo
Homes', could use 1.5mm2 for wiring, have a 10A power fuse and string
it all out to 20 or so double GPOs? (maybe even placing wiring and
lighting of the same single fuse?)

Nothing like reverse bureaucracy to make your day

This is covered by clause 1.8.5, which implies a more common sense
approach than the older more prescriptive formulas of the older wiring
rules. This clause basically says the number and type of circuits required
depend on the location, load, demand and any other special conditions.
They are designed to allow the Electrician to design a solution to meet
the requirements of the customer better than the old rules, possibly at a
lower cost. As some one else said, if you have a requirement for 100
mobile phone chargers, or other low power appliances, then you could have
a circuit with a 100 socket outlets on it, which would be quite safe. This
could also be wired in 1.5mm2 if the total load was less than the capacity
of the 1.5mm2 as derated by the installation method.

Having one 10A circuit would not meet this requirement for a normal house.
Note that however the wiring is protected correctly by an appropriate
fuse, and would not present an electrical danger as such.

 

[gav]

Is this to say that my new house, being built by 'Extremely El Cheapo
Homes', could use 1.5mm2 for wiring, have a 10A power fuse and string
it all out to 20 or so double GPOs? (maybe even placing wiring and
lighting of the same single fuse?)

Nothing like reverse bureaucracy to make your day

Nope. They'll give you 1 gpo per room, and it'l be a single.

 

gav wrote:

Is this to say that my new house, being built by 'Extremely El Cheapo
Homes', could use 1.5mm2 for wiring, have a 10A power fuse and string
it all out to 20 or so double GPOs? (maybe even placing wiring and
lighting of the same single fuse?)

Nothing like reverse bureaucracy to make your day

Nope. They'll give you 1 gpo per room, and it'l be a single.

And it will be behind the door.
--

David