Problem after maintenance!

  • Hey guys,

    Just started up with a coffee and when I turned to Servo power on. it immediately shut off and gave me an error (D1008 P-N low voltage)
    It happened one day after a qualified mechanic ran a big maintenance routine.
    It has to do something without it, because the robot isn't in production yet, I've been playing with it to learn a lot about it for when it actually goes into production.
    Can anyone tell me how to fix this? He replaced the capacitors, I think there is a faulty connection at the capacitors in the Power block.
    Kawasaki troubleshooting says the following:
    Main cause:
    1. Disconnection or connection defect of each harness between the MC unit (1KQ board)/1NQ board and the power block.
    2. Defect in the 1KB/1RB (arm control board), the 1KP (power sequence board), the 1KQ/1NQ (power cicuit board), etc.
    3. Defect in the power block.
    4. Defect in the MC unit.
    1. Check the connection harnesses.
    2. Replace the 1KB/1RB, the 1KP, the 1KQ/1NQ, the power block, the harnesses or the MC unit.

    Well, I did the first thing, but countermeasure 2 is nearly the same as buying a new controller...

    I'm pretty handy with electrical circuits and diagrams, so I was wondering what could've caused it.
    It says the voltage across P-N is 60 VDC or less when motor power is ON, or the connection between X212 (1KB/1RB board) and X502 (1KC/1KD boards) is abnormal. Registered as error only when servo is ON.
    Error level C: Abormalities without possibility of damaging equipment: Errors processed by servo software and AS software.
    What do they mean with processed by servo and AS software? The programming part? Because that's something that didn't change and it ran the software before.

    Thank you guys in advance! I've been learning a lot lately!
    Anyone have any experience with this error?

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  • Quote

    It happened one day after a qualified mechanic ran a big maintenance routine.


    He replaced the capacitors

    Why?........................... :censored:

    When motor power is 'called for', MC unit supplies 3 phase 210V to power block, via pre-charge resistor inside MC unit, power block converts AC to DC bus voltage, when bus voltage is reached - signal sent back from power block to MC unit, and contactor in MC unit disables pre-charge and supplies AC direct.
    When motor power removed, MC unit contactors disable and switch in discharge resistor to remove DC bus voltage.

    Check incoming supplies are balanced.
    Check F2 Circuit breaker.
    If F2 trips, the power block is usual cause (internal 3 phase bridge rectifier short circuit, or power amplifier defective)
    If not, then MC unit contactors/pre-charge/discharge resistor may be damaged, or circuit control board inside MC unit.
    Check harnesses between MC unit and power block are 'Clicked' in place.

  • Hello Kwakisaki!

    I've found the problem!
    I checked all the harnesses but they were okay, so I began disassembling the power block if I'm right? (picture)
    The "certified" Kawasaki mechanic forgot to connect C1! So Where you will see three capacitors connected to eachother on the power block.
    He completely forgot to wire 1 of the 3. See attached picture!
    The wiring was just loose in the controller so I think it could've done a lot more damage if the loose connections had been in contact with another component or shielding.

    I waited till the capacitors drained which is about 7 minutes according to Kawasaki manuals. Then reconnected the last capacitor.
    And there it was, no D1008 error anymore!
    Thank you for your explanation! It helped me understand the electrical drawings just a little better!

  • Yes, those leads come directly from bridge rectifier, so no DC Bus supplied to Power Amplifier section.....PN Low Voltage.
    - Those leads being floating could have created nice light show, puff of smoke or fire........ :down:

    I find it very strange that someone has replaced the capacitors on a working system, and not actually tested that the robot moves.
    - I doubt this was a Kawasaki Service Technician.
    - Sounds to me more like someone has 'overhauled this on a bench' and maybe left it part finished.....
    - If it isn't broken, no need to fix.....................

    Hey least its working and no damage/injury has occurred........Nice work........ :beerchug:

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