My homemade 9.6 kW garage heater. The case is a case from a "die attachment evaluator" that I could not sell. It uses a 230 CFM Comair Rotron fan. It plugs into a single phase outlet (range plug) of my phase converter. The yellow plug is the 3 phase plug and it is not compatible with the range plug, so one cannot be accidentally plugged into another.
The outlets on the heater are convenience outlets, 20A on separate legs of 220V. The switch that you see engages a contactor of the heater and also starts the fans. There is also a temperature sensitive switch wired in series. so that the heater turns off when temperature exceeds its limit. The heater element also has overheat protection built in.