Connecting to 240volt supply
Normal household 240 volt AC power (household 3 pin connection ) can run a caravan. Or off batteries DC connection. Caravan appliances such as fridges and hot water cylinders, can change automatically over to either of these power supplies. Connecting to 240v is easy if you can plug into a 15amp three pin connection. A 15amp plug has a larger earth pin than a 10amp plug. But when there is no 15amp outlet available such as some camping spots around Australia or most home/farm stays then you need to connect through a device such as a Ampfibian power connecter.
Unfortunately there are many backyarders out there that chop and change electrical plugs when they are not qualified to do so. This allows them to connect a 15amp power cord to a 10 amp outlet but also brings on these issues :
Potentially damage either, yourself, your house or your van.
The correct way to connect
The legal way in Australia, to connect a 15amp caravan to a 10amp power point is to go through the ampfibian power adapter. It's designed and rated to meet Australian standards.
The Ampfibian is a Residual Current Device (RCD) and circuit breaker all in one. What it does is allows you to connect your 15amp lead to a 10amp outlet safely . In the event your caravan decides to draw above 10 amps the circuit breaker will trip well before the 10 amp household power point or wiring goes into melt down which causes a fire or worse, electrocutes someone. It also will prevent a short coming back up the wiring and damaging your caravan equipment.
Air conditioning units in caravans can use between 5 and 10 amps on their own. On a side note they also do not run off DC power. Combined a microwave and the coffee machine could also draw the same. So with that in mind it's not that hard to draw 15 amps. You're best to play it safe and legal and get the right tools for the job.