Air Con supply + install from the bulky goods stores (Good Guys, JB, Appliance Online, etc)

Sorry post ended up in wrong area so I will repost it. Don't like my chances of making it in property if I can't even navigate the forum.
Below is my 2 cents worth

Have to totally agree with there is absolutely no way a 7kw unit should be on an existing circuit.
7kw needs a separate circuit. Look at the as3000 wiring rules. You don't want to run the risk of burning down the house. Depending on the wiring install and unit it could even require a 25-amp circuit with 4mm cable. You need to look at the min circuit amps and max fuse amps in the manufacture’s specifications. Even then the manufacturer’s specifications will state that the unit needs to be wired to local regulations (as3000). The largest unit you may get away with is a 3.5kw on an existing circuit and then it is still not recommended by manufacturers. You run the risk of tripping the earth leakage breaker because you exceed the earth leakage rating on that shared circuit for the breaker and if a TV or Radio is on that same circuit you can get noise interference from the inverter PCB depending on brands and the quality of their noise filter PCB's
Guys size does matter. Oversize and it won't work. When your house has been baking in the sun all day it is like a clay oven. Cool the air down too quick and the unit will keep cycling off on temp. Then the structure heats the air back up quickly and you have a unit that is short cycling on/off. The unit should be sized so that the room temperature can be cool down at a rate that allows the inverter to start ramping down and maintaining minimum capacity.
With the tenant not cleaning the filters and an oversized unit your looking at problems. If the returning air temperature is too cold or dirty filters the indoor heat exchanger loses its efficiency as there is not enough heat passing it to boil off the refrigerant causing liquid migration back to the swing or scroll compressor smashing it or washing out the oil seizing it. Another problem is the unit can reach dew point and the casing and fan scroll will start to sweat. This will cause it to start to grow mold. It’s like putting a V8 in a mini and trying to drive at a constant speed.
Manufactures warranty won't cover compressor damage as a result of oversizing.
Then you need to look at other issues on heating cycle. When running in reverse cycle with the indoor heat exchanger now being the condenser (smaller surface area) and the outdoor heat exchanger now being the evaporator (larger surface area) if the system is oversized you run the risk of activating high pressure safety control. Like it has been mentioned before a smaller unit is better than a drastically oversized unit.
Most reputable installer will come out and offer a free quote.

 

Cheers Womble, thought it was odd, good size then, thanks

 

Not sure what area/city you're from @Orion but it's possible to get a 7kw Mitsubishi Electric/Fujitsu for $2100 supplied & installed in Sydney metro with its dedicated 20a circuit breaker (25a for fujitsu)




PM me for details