Downrating of TPS

[Moondog55]

We need a new run for our new oven and the biggest we can fit to the board is 10mm.
Sparky says that because it is partly running in an insulated wall the load has to be down-rated to 42A
I understand the need for this but the range needs a 67A supply.
I'm reading the old AS3008 and in that the current carrying capacity of 10mm<2 is 64A in free air.
Enclosed in conduit 42A
But I can see nothing in the old standard about running TPS through an open heat conductive SHS with ends open to allow convective cooling.
We'd like to run the new line under the eaves and down the steel cladding on the outside of the house but our young sparky says that will still limit the current to 42A; he also says he wants to do a neat job but our feeling/want / need is for the maximum allowable load carrying capacity not aesthetics

In the old forum I remember some discussion about this and the experienced there said that it was partially dependent on the size of the steel SHS.
If this is so what size of SHS is needed to be the equivalent of spaced free air?
Any links I can share with the young bloke would be appreciated as we can't physically fit 25mm<2 to the board according to him.

[Moondog55]

This range needs more power in total than the main in to the house which is supply fused at around 63A I think and that is the same as the main switch at the board.
A bit of a crazy situation here when the state government wants us to go all-electric ASAP but won't give us the infrastructure we need to do so. We have solar but no battery as yet
The new range is the F&P OR90SCI6X1 induction 5 cooker top + oven and a really nice unit
It can accept 2 and 3 phase supplies as well as single phase.
Advice welcomed

[r3nov8or]

Mate, you're a chef. You don't want induction

I wanted to go induction on a new 900mm range, but the wife wanted a gas hob, and, same as you, a full electric range needed more than we could get from the infrastructure (without an expensive upgrade, and the oven was enough itself)

[Moondog55]

I think I do want induction, safer and cheaper to run and so much faster I am told

[r3nov8or]

Certainly much easier to clean etc, which counts.

Not sure about cheaper assuming your current oven is electric and the hob is gas. All the upgrade work/expense you need to make it happen will mean the ROI is a fair way off from behind positive.

If you haven't yet, see if you can book a session at the likes of E&S to take induction for a run. Just make sure you like it before committing

[Moondog55]

We have a demo and lesson booked for today

[Moondog55]

The return on investment would be getting rid of the old gas water heater and going to a heat pump HWS and losing the gas entirely. The supply charge exceeds our usage and that's probably where the savings are.

[r3nov8or]

That's a good point

[havabeer69]

So how are you getting around the 63amp total supply problem then?

Or is it just a case of your own problem if you try and run all burners at once and try and run the kettle?

[Moondog55]

So far F&P are being coy [ or obstinate] about that issue.
The sales person at E&S thinks it won't be a problem but has asked for more details from the company.
Our young electrician thinks it won't be an issue as we are not likely to be using all the hobs units at Boost all at once and the oven at the same time but I personally am skeptical. If we need to run two conductors to the range I'd like to do it now rather than have to have an expensive tradesman come back in the future.
At the same time I think we need to look at a battery; there being an article on the Solar Quotes site on how having a big enough battery can "Stiffen" an inadequate mains input. But I still think that a fully electric home either needs 3-phase power or a 100Amp single connection

[Moondog55]

Well we won't be buying anything from F&P.
P&P are now telling us that unless we have 67 amps available we will get lots of nuisance tripping
Basically they are selling cookers that really need a 3-phase connection as domestic units but not disclosing that information.
A real shame as they are nice units. Maybe 15 years ago we could have afforded a triple connection but not now. Maybe we should go back to cooking on wood fires and wearing animal skins to keep warm in winter/

[havabeer69]

I mean you can still have a normal style electric cook top? Just not a super high power induction?

Have you looked into getting some new (but bigger) cable run from the power lines? Something rated for 80 - 100amps and just getting a new main fuse?

[Moondog55]

I mean you can still have a normal style electric cook top? Just not a super high power induction?

Have you looked into getting some new (but bigger) cable run from the power lines? Something rated for 80 - 100amps and just getting a new main fuse?

Yes and not affordable via PowerCorp, Many thousands of dollars; a big battery might be cheaper