Hi everyone, I am new here, and recently we have met a situation which is really weird, A 6640 gripper robot at our plant alarm with "34316 Motor current fault"(rob1_5) first ,then axis 5 lose the zero point(other axis are fine),then we re-calibrate axis zero position, and after this it could not move even in the very slow speed, constant alarm with "34316 Motor current fault"(rob1_5), we replace the main drive/SMB cable(from controller to Axis 1 base),check the Axis 5 mechanical and motor cable ,encoder cable, connections are fine ,but after this it can move in slow speed(with 25% automatic mode), but still when we add up speed ,it run with alarm,,further more, in rest time ,we re-check/re-connect the motor/resolver cable, when we recover ,it shows very bad signs, it could not move with even 10% speed..some guys suggest to check the gearbox oil,and when we open the bolt(add oil one), some oil comes out, oil is clear,to all surprise.. after this, the robot recovery as good as normal, with 100% speed no alarm.... and in all this process, we have monitor the Axis 5 motor torque,it show some sharp waves(both in positive and negtive,middle is zero) when alarm happened, I have no ideas about the reason, and here is the pic, pleas help me on this....thanks a lot
I don`t know if this type torque wave was caused by encoder signal transfer disturbance? or it was caused by mechanical collision(inside the gearbox)?
as i see the manual, when collision detection happened, there maybe exist such torque wave, but I think this was not same with our robot`s fault ,as we didn`t alarm collision(above pic, it did not stop when these four sharp waves arrives, later it when sharp wave become heavier upon the limit, the robot stop and alarm)?
Help: IRB6640 constantly alarm with "34316 Motor current fault(rob1_5)"
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heroche -
March 14, 2017 at 8:05 PM -
Thread is marked as Resolved.
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Kinda sounds like a brake dragging, but (I think) you said you checked the mechanical for binding.
I suppose it could be intermittent. Depending on what load you have attached to the end - next time it won't go at all, release the brake and see if it will move... -
Yes,Iowan,first, you mean when robot moving automatically, the axis 5`s brake fail to loosen,at this time motor`s resistance become larger to cause this alarm?
second, today, it happened again(also lost the Axis 5`s zero point with 38209 Resolver error,Too low voltage from X or Y resolver signals), and we release the axis 5`s brake manually, and we push the Axis 5 to move around, we didn`t feel any abnormal resistance,also today we have change the gearbox`s lubrication oil, but still alarm happen
third, this robot only alarm with 34316 which was too large torque current deviation, what the difference between 34316 and 34317( a too large current
deviation) and collision detection?thank you so much, this robot almost drive me crazy....
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it looks like damaged cable
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you mean axis 5 motor's resolver cable?
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or the resolver/encoder failing internally?.
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A 38209 Resolver Error can only be the SMB, resolver or the cable in between. I have seen this same problem on an S4C IRB6400 when there was a break in the shield of the resolver cable. The unshielded section of the cable resolver cable allowed voltage to be induced from the nearby motor cable and it caused mostly current errors but then the occasional resolver error. Sometimes it would move like the commutation was wrong. Jumpered the shield across the bad spot to verify and then replaced the upper arm cable for the fix. Coolant had gotten in thru a crack and dissolved a section of the shielding.
My comm/nav training keeps me aware of the proper shielding needed for signals - I include checking shielding when checking cables. -
We have seen this same issue on many of our robots. Most seniors here know of the seal issue with oil being pushed through the motor.
Have any of your robots been upgraded with the new oil seals in the motors?Yes, you could possibly have a brake or cable issue, but in the 7 years we have been using the IRC5 robots I have only seen a couple of brake issues. 90% are caused by the oil reaching the brake. We have had robot's fall completely due to this issue.
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We have seen this same issue on many of our robots. Most seniors here know of the seal issue with oil being pushed through the motor.
Have any of your robots been upgraded with the new oil seals in the motors?Yes, you could possibly have a brake or cable issue, but in the 7 years we have been using the IRC5 robots I have only seen a couple of brake issues. 90% are caused by the oil reaching the brake. We have had robot's fall completely due to this issue.
Yes, hello, did you mean the oil seal of gearbox fail to seal ,then the oil run into the brake which cause the motor fail to brake??(but axis 5`s brake is at the end of motor,the oil should never be there?)
and also we did not update any oil seal of gearbox...
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Yes, the oil seal on the shaft side of the motors is failing. This allows the oil from the gearbox to move through the motor and into the brake.
You can also see position faults due to the oil getting into the resolvers.
There is an updated oil seal, but you have to buy the complete motor. They are actually installing two seals together.However, this isn't fixing the problem. We tried to convince them that the gearboxes were building pressure, and this is was is the root cause of the issue. Oil being pushed through the motor seals and through the motor is just a result. We have actually installed pressure gauges on some gearboxes and have seen a substantial amount of pressure building.
Trust me, if you are checking oil on these robots while they are running production and therefore up to running temperature, "BEWARE!".
I have seen several boys get hit in the face with oil when taking out the "FILL PLUG". Yes, the "FILL PLUG". Not the drain plug.
We have seen up to 8-10 feet streams of oil come out of axis 3 gearboxes when checked.If your next question is how many have we seen do this? Hundreds and I do mean high hundreds.
ABB is fully aware of this issue because they hired a specific guy just to be a project manager over this problem because it was causing so much
downtime for customers.The axis 5 motor cover can be pulled off to see if oil is in there, but you have to remove the wrist. Axis 5 is actually pointed up into the upper arm.
You will see axis 5 sticking out and unpainted in the picture. -
If axis 5 brake is not holding, then a fouled resolver could be the issue for the resolver error.
Since it's easy, I would try another SMB first if you have another.
One way to check the axis 5 resolver cable is to unplug connector SMB4-6 from the SMB and compare measurements with axis 6. The axis 5 values should be about the same as axis 6:
X5 Pins 4-to-16 compared to X6 Pins 9-to-21
Y5 Pins 5-to-17 compared to Y6 Pins 10-to-22
EXC Pins 7-to-19 compared to EXC Pins 8-to-20Several times I've had this error caused by a bad shield. I would also verify continuity of the shield from connector SMB4-6 Pin1 to the shielding near the axis 5 motor FB5 connector.
I've also had the spare part luxury of being able to disconnect axis 5 motor connections and connect another motor to verify a bad axis 5 resolver. Hate to pull a wrist without making sure.
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Yes, the oil seal on the shaft side of the motors is failing. This allows the oil from the gearbox to move through the motor and into the brake.
You can also see position faults due to the oil getting into the resolvers.
There is an updated oil seal, but you have to buy the complete motor. They are actually installing two seals together.However, this isn't fixing the problem. We tried to convince them that the gearboxes were building pressure, and this is was is the root cause of the issue. Oil being pushed through the motor seals and through the motor is just a result. We have actually installed pressure gauges on some gearboxes and have seen a substantial amount of pressure building.
Trust me, if you are checking oil on these robots while they are running production and therefore up to running temperature, "BEWARE!".
I have seen several boys get hit in the face with oil when taking out the "FILL PLUG". Yes, the "FILL PLUG". Not the drain plug.
We have seen up to 8-10 feet streams of oil come out of axis 3 gearboxes when checked.If your next question is how many have we seen do this? Hundreds and I do mean high hundreds.
ABB is fully aware of this issue because they hired a specific guy just to be a project manager over this problem because it was causing so much
downtime for customers.The axis 5 motor cover can be pulled off to see if oil is in there, but you have to remove the wrist. Axis 5 is actually pointed up into the upper arm.
You will see axis 5 sticking out and unpainted in the picture.Actually, We replace the axis 5 and 6(although we didn`t know the root cause) last week, and from your experience, I remove the cover of axis 5`s encoder and brake, and we don`t find any abnormal oil,the encoder/ brake shaft was clean,no sign of oil(I am not sure if we check the right place..)we did not remove the motor shaft side out(and yes we don`t situation on that side) ,because that was difficult...,below was last day`s picture..
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and since we replace the axis 5 and 6 last week, no alarm shows any more till now...
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Please forgive the zombie bump, but the info here helped me get a line back in production. Thanks to all who posted in this thread.
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Yo tuve el mismo problema.
Era un pin suelto del cable XS1.