The capacitor suggestion was for it to be directly across the output of the DC to DC converter. The reasoning behind it is for it to supply the fast current spike that may occur at the instant the SSR closes due to charging any input capacitors on the pololu. This current spike would be very short but may be enough to trip the over current circuit in the DC to DC converter. It would be too short to trip the circuit breaker.

Les.

Hello Les, Thanks for your reply. Is there any difference put it in the pololu input or on the DC converter output? I will try to put on the output later to test. Apparently I have tested the motor driver with bigger model of DC converter that supplies 1000W. This DC converter do not have such problem. But it is weird because I am not even attaching the motor and running it in the first place.

 

Good point. The mystery remains.

Yes, I have tested without connected motor, pure pololu driver only. The weird thing is the driver is on when I turned it on first time when the main power supply on. The moment I pressed E-Stop and disengage, it turns off.

 

YES. If you put it on the poloiu input it will produce a larger current spike as when the SSR closes as it will have to rapidly charge that capacitor as well as capacitors inside the pololu.

Les.