840Dsl motor drive damaged again !?

[wendaiyu]

Hi, guys, how’s going?

We have one 840Dsl milling machine. Yesterday there were alarms on axis Y_31:
230001 Power unit: Overcurrent. Fault cause: 1b bin;
230021 Power unit: Ground gault. 4726;
25201 Axis Y_31 drive fault.

We checked the motor drive and found out X11 (24V for motor brake) was short circuit.

So we replaced it, but after we powered the machine up, alarms showed up again and X11 on new drive was damaged again.

We checked resistances on Y_31 power cable and they looked like ok.

Could you give us a help to figure it out?

Thanks a lot.

 

[wendaiyu]

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