My nuwave oven shuts down after a few seconds, would suggest a sensor, useful husband, how can we fix it we are in australia please

Could be control board failure

Try a higher rated outlet....

Had you set the time if it had no time programmed in it didn't have anytime to run.

If you use a sensor function, the sensor may be obstructed, please clean the sides and top of your microwave with a dishcloth, warm water, and soap to dislodge any rough or stained spots.
If setting a timer, when setting to bake please pay close attention to the unit of measure so that you set it right, minutes vs. hours as you may leave the oven to do its business and return without noticing it did exactly what you told it to do but you had thought you entered a longer time.

It thinks its overheating, and the (faulty) thermal shutoff is shutting down your unit.
fix: since repair parts for household appliances are unavailable (parts are available for major
appliances only), your fix is to replace the microwave.
Or give it to the handy kid down the block who will disable the thermal shutoff and use it to
melt plastic stuff for demented puerile YouTube videos...

You can download manuals for free from NuWave website:

https://www.nuwaveoven.net/b335/asp/part/order_manuals.asp?

We are all in the same boat. It is very annoying. I think it is a sensor tripping.

Remove the top cover of oven, there should be tec screws on the bottem of unit to remove the cover, check for bad relays,fuses and fuseable links that could have finaly gone bad.

I would suggest that you try it for a minute or so on the very lowest power level and see if it shuts off. If so, please post again with more detail about how it fails, such as whether it loses all power as if someone unplugged it or just acts as if someone hit the STOP button.