Motoman UP20 and XRC 2001

Hello Everyone,

I hope that you are staying safe.

I'm helping a friend getting a Motoman UP20 and XRC 2001 back to service in a welding application, I got few questions which I appreciate if someone can advice or point me to right direction.

Some history: These are two separate used units which we are putting together, when I connect the manipulator to the controller got few errors mostly related to backup batteries and emergency circuits.

Managed to find my way using the manual to disable some of the external emergency circuits for now just to test the system. At the moment when I start the controller, I get only two errors both related to backup battery, which is an achievement so far!

I select Reset to clear the errors, then all seems normal but I'm unable to switch the servo ON.

When I enter the robot page and get to the messages, I have couple of messages:

- "Master sealing OFF". (Not sure what this means!)

and

-"Robot is stopped by P.P. emergency stop". reading other threads here, I believe this is referring to the Programming Pedant emergency stop. I have tested the switch, it is working, but the message does not change when I press or release, I traced the wires to a safety relay (Omron G9SA) installed on the inside of the door with other relays which are not engaging, this is not surprising as some of them are connected to external wires which are not connected. Related to that, I have just seen this switch is connected to CN43 so I will check this tomorrow, meanwhile if you have any thoughts please let me know.

Is the wiring of the safety relay (Omron G9SA photo attached) available anywhere in the manual or this is application specific ?

The other question I have whether any sort of initialization is required at this stage or simply complete the connections then manage to turn Servo ON and follow the Home Position Calibration procedure?

Please excuse me if I'm missing the basics here as I'm new to all this.

Attached are a photos of the screen and the safety relay with the wires of the Programming Pedant emergency stop wires marked.

Thanks!

Some updates:

So I have checked CN43, it get wires from the dead-man switch and the rest goes to the safety relay mentioned above, the Safety relay is not getting any power, have checked the wiring which simply goes everywhere, I will have another run of checking each wire tomorrow.

I have decided to power the safety relay directly, it worked, and the P.P. Emergency stop now gone unless the P.P. emergency stop is pressed. I got the servo light flashing now.

I have not tried to operate the robot, as with me supplying the safety relay directly without the other smaller relays engaging (appears in the attached photos above) I might be risking the boards, or not ?

Pretty sure there is proper protection on the circuits but not sure if I should try to operate it as of now.

I noticed that the brake release on the controller does not work, does not light up, and does not release the brakes when pressed, not sure if this is linked to the safety relays circuit or this has another problem, any thoughts?

More updates:

I have checked today the brake release board and found that two fusees were gone, I changed them, then tried to release the brake, as I press the main brake release button FU2 blow again. I have disconnected the cable which goes to the brake circuit to the manipulator, changed the fuse, then tried the brake release, it seems that it is working fine, but not when the manipulator is connected.

I have powered the safety relay directly and tried the to press the dead-man switch, heard some contact, then an error 4111 came up as "BRAKE FUSE

BLOWN" this time is the fuse inside the board, had to pull the board out and luckily have a spare, changed it and now no errors are there on the programming pendant.

On the side i'm tracing the safety relays arrangements, a bit of progress but notice more external wires which need to be sorted.

The questions now:

1- Is there any way to test the brake circuit on the manipulator ?

2- Any experience with possible reasons causing these fuses to blow?

Quote from 95devils

1) Yes, ohm out the harness and the individual brake connections. The manipulator manual for your correct robot model would show the wiring pin out.

2) A brake is shorted out. Harness is shorted.

So I have checked the harness today, all seems okay.

I tried to follow the the attached schematic to check each brake circuit to the common, that was not so successful I have got many different readings between the pins some with very low Resistance below 1 ohm, few at 1.5 ohm and 3 ohm, other are just open, the measurements so far was not constant or give any clear indication on how everything connected, got resistance values between different axis breaks which was not expected.

Taking about this I must highlight the brake releases circuit fuse (FU2 in the attached) get blown when I press the main release switch (SB1 in the attached) before I press the individual brake release switches.

On a side note, the information I get earlier that the controller and the robot are not a match was not accurate, I have checked the serial numbers today and they match.

I was not able to find the pin layout of the manipulator power connector to identify the individual brakes pins, appreciate any input on the pin layout or this brake issue in general.

Brake_UP20.pdf

I got the pin layout, will give it a try, it is attached in case someone have similar issues.

UP20_Wiring_Connector.pdf

Some more updates, I have followed the circuit diagram for the brakes, attached is what I got the resistance for the three smaller brakes is around 1.5 ohm, with only 0.5 ohm for the larger ones, attached is my findings.

I have disconnected A1 which is the common for the three larger motors as these these lower resistance, the fuse is not blowing now, I was hopping that the other three smaller motors manual release would work, sadly that was not the case, not sure why. (A1 is from the brake schematic above)

I wanted to narrow down things, so I have kept A1 disconnected, then tried to operate the robot, when I press on the dead-man switch, I can see the brake relays operate, the larger contractors engage in the controller, in a second I get the attached error (1321 over current AMP)) with no movement on the robot.

Here is what I think is happening, the robot is trying to move to a cretin potion but as S, L,and U axis brake is not release so the motors are drawing more current than they should be.

What I'm trying to do here, is to see if the other three axis are working fine (R, B, and T), I want to be able to move them manually using the programming pendant, without moving the other three which are locked under brake.

The questions here are:

1- Any thought on the resistance I'm getting on the brakes ?

2- How to stop the robot from moving automatically to a set position when I press the dead-man switch whatever is that, but move manually axis by axis ( I was trying in the teach mode).

Diagram_Error.pdf

Hi again, today it seems I had a step backwards . I noticed that I left the brakes cable unattached inside the controller during yesterday testing, so I have connected back and tried again, as soon as I pressed the dead-man switch, the contractors latches and it blows the brake fuse again with error 4111 even with A1 disconnected. I do not have any spare so will have to get some tomorrow and start over with the wiring

.

I came across this post which make me wonder if my problem is somewhere else like the external wiring : Brake Fuse Blown

Still looking to solve this, and wondering, is it normal for the robot in the teach mode to try to move on its own by just pressing the dead-man switch without me jogging?

With all this the manual brake release is still not working.

Hi,

After all it seems that the harness is the issue, I have traced few of the wires and they seem that they are going to the wrong pin, not sure of the harness is from another robot.

Can anyone confirm that the numbering layout I'm going to follow is correct (see attached) I'm not sure about the pins locations within each block of the connector.

So it was the harness after all, it turned out that the blocks were installed upside down in the connector and pins 5 and 6 of each block are messed up, not sure why but might be a cable from another model or so.

The good news: all breaks are working fine now, I was able to jog the robot manually with all the six axes working fine but slow!

The bad news: I was following a the begeners guide in "Motoman XRC 2001 Controller Operator's Manual for Spot Welding" all went smooth writing a basic job, but when I was test running the job using the FWD button the robot moved for a bit then stopped with an Alarm 1318 Overvoltage (convertter) (0000_0000_0000_0001) tried to restart the controller couple of times, now this alarm pop up when I try to jog manually as well.

Any thoughts ?

Quote from Robodoc

Either the converter is going bad or the plant voltage is too high. What voltage do you read at the top of the KM1 on all three phases?

Thanks for your input. It is very unlikely that the voltage is too high as I'm using the mains voltage and that error came out during operation, however, I will check it out.

If the converter is faulty, any idea on possible reasons of that?

Is there a schematic/circuit diagram out there for the converter for me to test/repair it?

Well, I guess not much options here, I will start by testing the voltage then look at the converter to any obvious reason. I can see there are some units online for a replacement, but they might have the same issue as mine.

Thanks!

So After lots and lots of checking, I found that there is a 220W 12.5KOhm resistor located in the back of the controller next to the fan connects to the converter is faulty, I have changed it and the controller is working a gain with no errors on it, Now I'm keeping eye on it, and found that running the robot for few seconds get it to heat up really fast and really hot, if I keep going it will blowup just like to previous one, this resistor in case you are wondering is similar to the large one shown in this link they are referring to it as breaking resistor. This connects to JUSP-ACP25JAAY11

Was wondering if anyone had similar experience and if there is something obviously wrong here.