Made a dummy load with cooling fun.
A dummy load is ; https://en.wikipedia.org/wiki/Dummy_load
She has a circulation unit for the cooling oil, this is the speed controller.
At the back a fan is built in next to the radiator.
I got a nice radiator from a junk yard in the vicinity.
It was fortunate to me that I got a new-old-stock trochoid oil pump, but it seems to be a tad over-killing.
I made several types of load, this one shown below is of 50ohms, a standard type.
Not yet calculated the capacity, but I suppose this can withstand more than 3kw.