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View Full Version : Ducted air off single phase? or do I need 3 phase?















mixin
14th March 2007, 09:55 PM
We're looking at purchasing another home, and this one is 25 years old in an area that has underground power cables. The house only has single phase.

Will this restrict what we can run in the way of a ducted unit?

What's the biggest ducted unit you can run on single phase power?
One online estimate came up with a 14.7kw external unit.


It's a fairly large 4 bedroom, living, family etc place - all spread out, making it difficult to cool with 2 (or 3) split systems like we currently get away with in our 3br house now.


If I do have to get 3 phase put on, what sort of cost factor is there in getting 3 phase up to the house? (it's approx 12m from the street gutter to the box, and all uphill, so no idea where the current supply trench is located).

cross
14th March 2007, 10:42 PM
What's the biggest ducted unit you can run on single phase power?
One online estimate came up with a 14.7kw external unit.

Its fairly common to install a 7.5 to 8kW unit and zone it so that it will work in your living area OR your bedrooms at the flick of a switch. This is something to keep in mind, unless you need to cool the whole house at the same time you can get away with a slightly smaller unit and zone it accordingly. But without looking at your house its hard to make the call.

In regards to the power issue, obviously the ratings mentioned are heating and cooling capacity, not electrical energy used. Things you will need to know include, full load current draw of the airconditioning unit, size of existing consumers mains into your switchboard and an approximate of the existing load on the installation.

Just some things to consider, i know it wont help you much, but it would be really easy to determine what you need if you get a tradesman out to take a look for you and offer the appropriate advice.

mixin
16th March 2007, 01:38 AM
I ended up phoning my electricity supplier, who told me I needed a "Level 2 service provider" to install 3 phase from the street to the meter box.

Here's the site they told me to look up for a list:
http://www.deus.nsw.gov.au/energy/energy.asp

So anyway, I rang the closest one to me, and his response was "it's gunna cost a bomb mate, just get a Bonaire unit, they go up to 15kw in single phase & I've installed heaps of them, and it will have no probs unless you live in Buckingham palace"

So I looked up the Bonaire website & found this:
http://www.bonaire.com.au/refproducts/b015.html

It's rated at 14.7kw, single phase, but as noted above, there's a lot more to the ratings than a simple number, so I'll have to read the specs carefully.

I'd hate to think how many amps it's gunna pull on startup!

Timmo
17th March 2007, 10:00 AM
The unit has a soft starter which will reduce the start current.

I run an 11kw single phase unit without a problem.

If they weren't worth using they wouldn't build and sell so many of them.

You can go up to 15.5kw with a single phase inverter with Daikin.

dan76n
2nd April 2007, 09:56 PM
I have the Daikin inverter 15.5kw which is single phase.
It cools our 2 story 37sq home in QLD if that helps

mixin
2nd April 2007, 11:28 PM
Thanks Dan,

We're going with a 14.7kw Bonaire unit. If yours works well in Qld, considering the climate & space you're servicing, then mine will be brilliant in a milder climate & smaller house.