Electrical Sub board in shed.

[Lappa]

First minor hiccup. I'm serviced by Ausgrid and apparently in Sept 2016 they downgraded the maximum available single phase service fuse to 80A.

[Chris Parks]

First minor hiccup. I'm serviced by Ausgrid and apparently in Sept 2016 they downgraded the maximum available single phase service fuse to 80A.

For new installations?

[Lappa]

Chris. I've sent an email to Ausgrid for clarification but the reply didn't answer the questions so I'll phone them. The electrician today said he can only install up to 80A even with a new meter - my old one is 60A. It looks like a NSW Govt rules update to all providers. They still talk of a 100A service fuse but they now have a Meter protection device which is 80A. They can be combined in one but that unit is limited to 80A or they can be in series, 100A first then 80A to the meter or each meter if multiple meters. I'm reasonably confident it's for all new installations but not sure if it applies to existing installations that have work done after Sept 2016.
Hopefully Ausgrid will clarify tomorrow. Their technical section only takes phone calls to 11am.

additional info - found this

http://www.resourcesandenergy.nsw.go...nections/rules

[Lappa]

Reply from Ausgrid confirms 80A maximum fuse.

When asked what was the maximum current for a single phase residential the basic answer was

" The maximum rating of a meter protection fuse is 80 Amps under the new NSW Service & Installation Rules,"

plus references to existing components, neutral links, earth stakes etc. coming into play.

[Lappa]

As as I suspected, whole main board and meter needs replacement. In its original position, it's too high to meet current regulations. Moving it down will interfere with the front screen door so it has to be moved. Concensus is to move it to the side of the house - approx 4 metres. Old power points (5) in the old part of the house have to be rewired to meet current regs. Existing connection to shed to be placed on its own 20A circuit rather than piggy backing off existing circuit as a temporary measure until the sub board circuit is installled.

No change out of 4 big ones.

Sub board and circuit will have to wait

[BobL]

As as I suspected, whole main board and meter needs replacement. In its original position, it's too high to meet current regulations. Moving it down will interfere with the front screen door so it has to be moved. Concensus is to move it to the side of the house - approx 4 metres. Old power points (5) in the old part of the house have to be rewired to meet current regs. Existing connection to shed to be placed on its own 20A circuit rather than piggy backing off existing circuit as a temporary measure until the sub board circuit is installled.

No change out of 4 big ones.

Sub board and circuit will have to wait

oh dear, sorry to hear that.

[Lappa]

Two guys, 7 hours and I went from this


IMG_0525.jpg

to this

IMG_0561.jpg and this IMG_0562.jpg


plus all the old rubber and cloth wiring replaced.


Saving up now for the sub board

[Pearo]

Looks like it was a good investment even though the shed upgrade is delayed.

[Lappa]

After some discussions and great advice from NCArcher, I've decided to install a 32A sub board rather than the 60A I was originally looking at and what the Electrician that rewired the house suggested (the electrician was saying he always installs sub mains for the max. just in case of future developments)
The electrician that came around today concurred with NCArchers advice. I already have a 20A circuit to the shed that has two year old wiring to the house and now new wiring connected to it and the new main board.
This will be utilised for the lights, fans etc. and the sub mains will have two 15A GPOs plus a number of double 10A GPOs for the power tools.
So probably save a bit on the smaller wire gauge but should be easier to install.

[BobL]

After some discussions and great advice from NCArcher, I've decided to install a 32A sub board rather than the 60A
.
.
I already have a 20A circuit to the shed that has two year old wiring to the house and now new wiring connected to it and the new main board.
This will be utilised for the lights, fans etc..

Sounds exactly like what I did.

[Lappa]

The cable distance to the shed is about 20m. Is 6mm twin + earth TPS O/K? The guy reckons is good for a 40A sub board.

[NCArcher]

Yes, 6mm will be fine. Depending on how it's installed you could get a bit more out of it. The current carrying capacity changes with its ability to get rid of heat. So a cable installed in air can carry more current than a cable surrounded by insulation in a wall or roof space. With a longer run of cable the resistance of the cable increases and the voltage drop goes up. Max allowed voltage drop is 5% so 12 volts for 240V supply. Your run will drop about 6 volts.

[Lappa]

Thanks Tony. It's being installed in conduit running along a Bessa block retaining wall behind a lot of shrubbery. We use the same 5% rule for critical circuits in automotive as well.

[BobL]

I had a 6 mm^2 4C+E line run even thought the house doesn't have 3P because at that stage (2011) the street was going to be converted to UG power in 2013 and I was hoping to get 3P connected at the same time.
In the meantime I discovered VFDs and now have 11 of these in my shed
Now we are not getting 3P power in 2019 but I am not sure we will bother to get 3P power.

On another matter, it's a 40 m cable run and the mains V in the shed is usually around 240V but I have seen it as high as 252V and hot days like today it's 229V

[Sawdust Maker]

It's good to see Tony's consistent in his advice