Cerise,
The technical parameters of the Thermochef are as follows:
1. rated power: motor power 550W, Heating plate 1000W
2. Work voltage of main electric machine: 220-240V AC 50/60Hz Max rotate speed 8700RPM Min
I have ground nuts in my Thermochef without any problems, but i have only ground enough for a recipe - not 4 kg worth.
I am finding that most of the recipes for the thermomix work well in the Thermochef. However, I am always wary of mixing bread dough in the TC, as it can strain the motor. If a TMX recipe uses the reverse button, I insert my butterfly to stop the food from getting chopped up.
Hope that helps