Daewoo Puma 200 power unit

[umc1]

Hello Daewoo techs. I have a Puma 200 that was running ok , then it tripped the breaker on the machine. I have tried to disconnect the main spindle, the axis motors and I still got a hard short in the line. When I disconnect the MDS power unit, the machine turns on. Has anyone ever had this problem? could it be that the power unit is bad? Or am I not checking the line correctly. I am new at this and could use some help. The power unit is MDS-B-CV-185. Only when I disconnect the 2L1, 2L2 and 2L3 power lines from the unit, the machine turns on. When I disconnected the spindle and axis motors, I disconnected the motors and the units in the cabinet. I did this to see if maybe one of the two were the reason for the short. Please help.

[resuengineering]

take off the dc bus link (discarge first)

measure by diode test on a multimeter.
check from dc link plus, to all 3 phases
you should have resistance or no resistance on alle 3 phases.
swap the meter pins around and you should have opposit measurement.

or just swap power supply, it sound like that

[umc1]

Sorry for the late response. I hope this will help others that have the same problem. The problem turned out to be the power supply (MDS-B-CV-185).
I disconnected all the power lines and checked each line one at a time. Only after I would connect the power supply I would get the breaker to blow. Thank you for your replies and feed back on this problem. Lou

[MysticMonkey]

If it was the bus then it would power up and give you an alarm. I think your assumption that it is the power supply was correct. Which overload is tripping ? Is it before or after the hydraulics power on? Disconnecting the psu might be masking the fault by not allowing the cnc to power up to a point where it trips out.