RJ3iB controller wont turn on

  • it was working just fine until yesterday when suddenly it won't turn on. I have tried tracing the current and we have plenty coming in from main and going into the transformer. From transformer into estop unit i am getting 200 which should be good. From transformer into PSU i am getting 53 which seems low to me. From PSU i am getting 45 volts out on AC and nothing at all on DC. The PIL light is green but there is a red led on labelled ALM(assumedly alarm).


    Swapped the PSU with an old spate but nothing changed. I have a few more i could try swapping with if it comes to it.

  • it was working just fine until yesterday when suddenly it won't turn on. I have tried tracing the current and we have plenty coming in from main and going into the transformer. From transformer into estop unit i am getting 200 which should be good. From transformer into PSU i am getting 53 which seems low to me. From PSU i am getting 45 volts out on AC and nothing at all on DC. The PIL light is green but there is a red led on labelled ALM(assumedly alarm).


    Swapped the PSU with an old spate but nothing changed. I have a few more i could try swapping with if it comes to it.

    Input to PSU can't be less than 200V. Otherwise it won't start.

    Check why don't you have this from the transformer.

  • Checked them all, all good. Even the little fuses that you can only access by pulling out the PSU and the devicenet boards. Checked fuses on the servo amp, on the door panel board. All good

    F1 is not so important is this case - when 200V is not supplied to PSU, especially if changing PSU haven't helped, so it's definattely the problem with 200V input to PSU.

  • so how would i check the transformer? I think we have a few extras I could try but they have been sitting in storage for awhile so if i could know a way to check them before dropping them in that would be great

  • so how would i check the transformer? I think we have a few extras I could try but they have been sitting in storage for awhile so if i could know a way to check them before dropping them in that would be great

    I'd personally disconnect CP1 from PSU and check the voltage inside - mind it's AC and could be high, so carefully :smiling_face:

    Of course from the cables and plug side :smiling_face:

  • i only get 53 volts coming out of cp1, even when i test directly at the outlet where cp1 plugs into the transformer (under where the estop plugs in labelled OUT) still 53

    There could be a problem with the transformer. If I had one, I'd swap it and check again CP1, before connecting it to PSU.

  • well this particular controller is pushed up against the wall so getting transformer access will be a bit time consuming, forklift is rarely free around here. Ill definitely post the results when i get to it though

  • I have tried tracing the current and we have plenty coming in from main and going into the transformer.

    Are you REALLY sure that the incoming supplies are balanced and within tolerances?


    Personally I would be a little more thorough when troubleshooting supply issues by:

    - Power off and isolate at source.

    - Disconnecting ALL load side (secondary side) of transformer connections.

    - Power on at source.

    - Measure incoming voltages at both sides of breaker are balanced and within tolerance.

    - Measure secondary side of transformer voltages are balanced/within tolerance voltage levels.


    Doing just the above removes/eliminates all components accept:

    - Noise filters.

    - Connections/cables to and from primary and secondary of transformer.

    - Transformer windings or internal protection fuse(s).


    If the above is all good then according to the controller maintenance manual:

    - Power off and isolate at source.

    - Connect CP1 from transformer to PSU.

    - Disconnect CP2 at PSU.

    - Power on at source.

    - PSU should show signs of life.

    - Measure the voltage on CP1 and make sure voltage is still correct and balanced.

    - If not, PSU requires replacing.

    - If ok, power off and isolate at source.

    - Reconnect CP2 at PSU.

    - Power on at source.

    - Fan unit should be operating.

    - If not, remeasure CP1 and see if voltage is correct and balanced, if not, then fan unit has failed.

    - If ok, then all incoming and transformer secondaries are working.

    - However........from what you are saying something above is likely to be the source of your issue.


    As with ALL electrical connections, hazards exist so if you are unsure always use an approved electrician or competent person to carry out these checks.


    *** Note ***

    The above checks are based on information obtained from the R-J3iB controller maintenance manual.

  • I was taught in Fanuc's electrical maintenance class that there are non-reseting thermal fuses in line with each phase of the transformer secondary. If you look close at the total connection diagram you will see them. The only way to fix them is to tear apart the wiring loom coming off of the secondary. :tired_face:

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