Originally Posted by Stargeezer
... some appliances may be rated as 900w, but really run over 1kw.
There's the startup surge problem with motors (such as in air conditioners), but it would be strange for an appliance to continuously run over the rated power, unless it is supplied with power at too high a voltage.
Watch for microwave ovens: if you just go by the microwave power rating without reading the electrical specs sticker, you might think that a particular oven uses 900 watts, while in fact it put out
900 watts of microwave power and takes in
1200 watts of electricity to do that. It's the input power that matters to your inverter.