GM said:
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.