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Power Stage (IGBT) Over-Temperature Fault


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I have a question regarding an over temperature fault. On three separate occasions I have had an issue with the Delta-Tau Geo-Brick faulting with a 3F5 flashing on the status display. This immediately shuts down all of the motors. Can you give me some pointers on why this may be happening? Is there some way I can monitor the IGBT temperature in a PLC to help diagnose the issue? If so could you provide some sample code?


I have been unable to clear the fault on one of the Bricks, is there a way to reset this?



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Hello, John,


For Geo Brick Drive, we monitor the junction temperature of each motor IGBT. Technically, when the motor IGBT reaches the over-temperature threshold value, the drive will trigger the over-temperature fault and shuts down the motor IGBT.


The most common reasons responsible for the over-temperature fault are:


(1) The total average output power of Drive exceeds 60% of (axes number * rated output power per axis). When drive is working in this condition, the drive may trigger the over-temperature fault over one hour operation time.


(2) The fan of the drive stops working. Without fan, the motor IGBT will much more easily achieve the over-temperature threshold value and then trigger the over-temperature fault


(3) With higher ambient temperature, the total output power is De-rated. Above 40°C,de-rate current output by 2.5% per °C. It is because the motor IGBT will trigger the over-temperature protection with even less output power.


Please refer page 240 of the manual(http://www.deltatau.com/manuals/pdfs/Geo%20Brick%20User.pdf), it provides the sample PLC to monitor both bus voltage and IGBT temperature.


To better understand the over-temperature problem you have, I have some questions:


(1) In your post, you mentioned that you can not clear the fault on one of the Brick. On how many drive, you saw the over-temperature fault? Did all these drives show "3F5"? Could you please let me know the SN of your drives.


(2) In which condition, you encounter this over-temperate fault?



Please feel free to contact me if any further question you have. Thanks!


Best Regards!


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  • 2 weeks later...

Hi Jimmy,


Thank you for the additional information. The fault did finally clear on the Brick after two days. I used the example code you mentioned, when faulted the temperature values were reading either -45 or 498 degrees, the 8 bit raw data was either 0 or 255. Once the Brick cleared the error it was reading from 29 to 40 degrees. The fault code on the Brick at was 1F5 a couple of times, otherwise it was 3F5, so the fault was evident on both axis 1 and axis 3. The latest error occurred after the Brick was powered up and left idle, the drives were not phased or moving. The error has also occurred when the motors were operating, all of the axis were halted when the error occurred. We are implementing a PLC to monitor the temperatures of the IGBT to better diagnose the issue. The model number of the Brick is GBL4-C0-500-14M00030, serial number is "C0008YSY".


Can you confirm that the maximum average output for this drive is 12 amps? Does that mean that the maximum each axis can draw is 60 percent of the 5 amp continuous rating or 3 amps?


Kind Regards,


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