Allen-Bradley Kinetix 6000
We have just finished repairing this Allen-Bradley Kinetix 6000 28kW converter with great success.
Our customer said there was a smell of burning before the motor stopped and the unit went into fault. A 24V then tripped in the panel.
When we removed the covers it wasn't long before we found the issue. There are 2x 24V supplies which are switched out to the motor brake, and one had failed in a bad way. The main switching device had burnt so badly the board had carbonised and the copper had become severely oxidised. The switching device was unrecognisable however we were willing to use reverse engineering to work out what this should be.
We knew the brake was 24V so a safe assumption is to double this for headroom. The package was a D2PAK and the gate pin was being pulled low by an optocoupler so we knew it was a P channel device. We filtered down all options and went for a 50V 35A device which was the highest current rating in that package.
We got to work removing the carbon from the board. We were lucky in this instance as the heatsink of the device was the PCB all the way through to the underside. We built up the board using copper and solder making connections as we went through to the underside. Finally we attached the new device and overcoated with conformal coating for protection.
Finally we powered up the drive after giving it a thorough clean and service, enabled both brake outputs by driving the optocoupler and observe the 24V switch out to a 10A load. That was enough to call it good.
Another drive saved from the scrap pile, such a tiny fault would have caused this to go to landfill, with a bill of ££££ for a new one.
