Thread: A 3HP (15A rated) DC in a shed

I think Moph is saying that there are two ways an electrician might size a circuit
using the Standard's guidance table, or
by using the Standard's method for determining the applied load, or is it that the maximum load is limited via a breaker?


now as I've followed the discussion, what I might say to an electrician is "I want to put some biggish (4 or 5 Hp) power tools in my garage. The tools come with 15 or 20A plugs. I'd only be running one or at most two of them (e.g. band saw and dusty) at a time. What do you recommend?"

I'd save any reference to "some bloke on the internet" till after I'd been advised "you'll have to run 2 new 20 A circuits from your main switch board."
and in that case I'd likely phrase the internet reference, "oh, I've been told that the Australian Wiring Standards has a provision that allows multiple 15 or 20A outlets (or machines) on a single circuit provided there's a breaker that will trip if more than two machines are turned on at the same time. Is this true?"


and of course, I recognise that I need to ask a qualified electrician for advice and engage the electrician to do the wiring.

But what I'd like from the electrician is an explanation of why I'm receiving a particular recommendation.
For example, is running 2 (or 3) standard 3 core 2.5 mm^2 circuits cheaper because to install a heavier grade cable would mean that I would be charged for a whole roll of the heavier cable?

Originally Posted by NCArcher

I am an electrician and all I will say on this is if you need advice on electrical matters at home, ask your electrician. He is best qualified to give advice.

Is what I wrote wrong? If I'm not, what does that say about all the sparkies who have given conflicting advice to others on this forum?

Also note that my advice was "to ask the following questions" not tell them what to do. I see it as an ideal way of separating out the sparkies who know their stuff from the rest.

Ian's post above mine pretty much hits the nail on the head.

I think NCArcher was more responding to BobL's posts which, on reading again and in isolation from the other discussion, are probably too detailed.