Makes sense.
Europe has 220-240 volts at the standard wall outlet also.
Our kids had their kitchen remodeled recently, and added an over the cook top microwave vent combination by LG. It's a nice oven, with a telescopic vent system.
An electrician did all the wiring, and added ground fault interruptor outlets, and new switches. He tested each circuit for correct draw.
When ever they run the microwave for more than a few minutes, it trips the circuit breaker. It is not on the same circuit as the range cooker, fridge, or dishwasher.
I'm thinking maybe it's the microwave and told them maybe they should call for warranty service and have it checked.