What size power cable do i need for an 8.2kw/9.1kw Split Air-Con ?

G'day,

Be careful about going on to a building site - you could get yourself into a contractual nighmare. If anything at all goes wrong they will blame you because you were on site even if you didn't cause it.

$350 probably is reasonable anyway - you can do it cheaper but I doubt you could get many other contractors to do if for that price.

Other stuff aside 9kW aircon sounds like a 3.5 HP unit (kW refers to the cooling capacity not motor size usually but you need to check....) For this you will need a 32 amp circuit which will need at least a 6mm cable. It usually says on the aircon name plate what the circuit breaker size should be - from this you work out your cable size. 6mm PVC insulated cable is always stranded - be really hard to bend otherwise.

Make sure the incoming supply to the house is big enough too.

Thanks for reply j.l, The $350 estimate by the Supervisor was just to run the cable for now. It doesn't include cable cost, clips, circuit breaker in the meter box or connection to the air-con.

I reckon i can easily run the cable myself within 2 hours because there are no ceilings up yet and the sparkies won't come back now until the ceilings, white set plaster, all cabinets, bathroom/laundry/floor tiles are in.

There is 3-phase power being put in because of some equipment i want to run in a rear workshop. Does that imply there will be plenty of supply to the house?

thanks.

"dude" wrote

Since the ceilings aren't up yet, i thought it would be easy for me to run a cable and clip it to the joists/hangers myself over the easter break, allowing 3m-4m slack at the end of the family room and also at the meter-box. It's a total length of 31m.

Does anyone know what rating 3-core power cable do i need? Is 20 amps okay and do i need to use the solid core cable or will the stranded stuff be okay?

thanks,

***** Two things you should note:- 1) You obviously haven't got a clue about electrical wiring or appliance current ratings,hence your silly question about cable size and 2) in any state or territory in Australia it is totally illegal to carry out 240 Volt electrical wiring without the appropriate licence.To do so would automatically make your insurance policy null and void.Should you not have insurance and you are relying on the builders or bank loan insurance,in the event that you even so much as touched a tool on site,they would drop you like a hot sloppy turd.

Just forget anything about DYI,bite the bullet and pay the builder,not only for running the cable but for connecting the appropriate bits at ech end.

Brian Goldsmith.

Not strictly corr4ect , some others apart from a sparky can pull the cable BUT it needs a sparky to connect it. Either way this bloke shouldn't be contemplating it .

One suggestion is to ask around and try and find a cooperative electrician - they do exist - they can tell you what cable needs to be used and how it should be run. Once the building work is complete, they can come and check the installation and do the connections at each end.

That said, most electricians will still charge a couple of hundred bucks to come out, install a breaker for the A/C and do the connections.

The bloke installing the split system will charge around $800.00 or so to do it all including electrical , BUT adding the cable from the board to the unit will save quite a bit . I could mention OHMS law but maybe I shouldn't

6mm stranded (doesn't come in solid). Clip every 600 mm in ceiling (above insulation if possible)and make sure it can't be stood on or damaged.

Hopefully that $350 includes running the wire and making the connections at both ends.

The supervisor may object to that, he has the responsibility for safety on the building site, and that includes keeping you out.

Bye. Jasen

6 mm sq. cable (they stock this at bunnings, or you can go to the trade counter at Haymans etc) Unfortunately this isn't cheap, and typically will cost over $400 for a 100m roll.

The price charged by the builder sounds a bit steep to me. Actually a blatant rip-off if they arent supplying the cable too. I would at least get other quotes

You could consider running it yourself when no one is there, then inform them that you arranged a licensed electrician yourself to do the job. Im sure you can bullshit your way out of it, specially since they are taking you for a fool with that outrageous quote. Or maybe play it safe and just arrange your own electrician to do the job if its any cheaper.

If the builders are that much of a rip-off merchant, and you decide do the cabling, they might even try to remove it, in which case you might have a problem on your hands

The other option is to do it yourself after construction, while not a fun job, it can be done, or get the air-con installer to do it when he puts in the actual unit

If you have 3 phase coming to the place, running this air-con shouldnt be a problem, unless you are building some massive mansion that is full of massive power loads already.

Thanks for all that kreed and to all the other posters.

Yes, this builder knows how to charge for extras and i bet the tradesmen get only a small fraction of what they charge.

For example, at the sign up stage the builder charged us $810 ($270 x 3) for increasing the width of three doors from 720mm to 820mm. We had no choice but to pay.

When i was at Bunnings I worked out the price difference myself between a 720mm door frame versus an 820mm one and also the extra for the 100mm wider door panels and it came to less than $50 each.

I know for a fact that the bricklayers won't get extra, nor will the fixing carpenter. When i queried this cost, he said it was mostly an administrative charge. It seemed like a bit much to me. That was just one instance.

He would be claiming it as a planning varience , but if the plans were not in it should have cost about $80.00 , he pocketed quite a tidy profit on this .

Not that I have any time for builders and their rip off tactics, but if you are talking about a spec home don't forget that the frames have to be adjusted to suit during manufacture. One other thing, shouldn't you be putting in a 3 phase ducted air conditioner in a large new house, assuming you live in a hot area?

tradesmen

3) a

not

you

Correction: 3-phase ducted aircon AND compact fluorescent bulbs - need to be energy conscious.