@dc42 I am a bit confused since the duet 3 pin out diagram description says this:
2-pin JST VH OUT_1 thru OUT_3: these are intended for extruder heaters or fans. Maximum recommended current 6A each. If you connect inductive loads to these outputs, you must use external flyback diodes.
Does heater outputs has flyback diodes built-in?. I am trying to control 24VDC contactor via out9 but it seems it draws too much power and thus resets the whole system. I am going to give it a try with heater outputs but I am not sure if there are flyback diodes on them.