Dynamic Brake failure
I powered up my Powerpath 15 today, homed it and loaded a program. I never turned the spindle on. Approximately 5 minutes later I heard the drives shut down and an error on the screen that said "Dynamic Brake Failure" I hit escape as I was prompted rebooted the machine and couldn't get the fault to clear.
I checked fuses and I checked the resistance on the braking resistor and they were OK. Any suggestions?? I'm not an electrician and my skills are pretty weak in this area. Is there something that routinely goes bad with these? Any help or suggestions would be greatly appreciated.
Thanks, Pete
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Is there an over-temperature sensor on the braking resistor? If so, it may have gone open or there is a bad connection between the sensor and the rest of the control. If no temp sensor, then something in the spindle drive has failed, or in some way is sensing the braking resistor is bad.Originally Posted by Gncc50
Is this a braking resistor on the axis drives or the spindle drive?
Jon
Does the PowerPath have the Dynamic braking master and slave units? The EZPaths do have these. They fail on a regular basis. They have overloads that have red and black switches to trip and reset the overload on them. These sense the voltage at the spindle motor and go into conduction to the large 6000 watt, 6 ohm, fan cooled braking resistors.
Each has a small schematic on the face of the box and a terminal strip with about 6 x 2 wires.
I have seen these go open and thus not brake the spindle (dump energy). I have also seen them go into conduction when they should not.
There is also a resistor in the Yaskawa spindle drive and two fans on the back of it. Standard maintenance is to clean these fans on a regular basis and the Yaskawa manual states that these fans should be replaced every 5 years to prevent a failure of them.
George
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
Feel a little foolish....... again
Yes George it does have the system that you described. I removed the resistor and the fan was absolutely filthy almost plugged. I did notice the braking unit mounted on the inside of the door and I noticed the switches. If I wasn't so brain dead I would have noticed that they were also tripped, a simple reset and all is fine. Your recommendations on the fans is certainly a good idea. I noticed the one down by the spindle motor is also filthy. That will be the next to be cleaned. Are the fans 120 volt? I am going to replace both as soon as possible.
Thank you George, your valuable time that you put into these forums is greatly appreciated.
Pete
Problem came back.
I am getting the same dynamic brake fault. I reset the braking unit with the black switch that you described. Sometimes it runs for an hour and sometimes only a minute or two. It is faulting out even when the spindle is turning. I have cleaned the resistor and the fan seems to be fine. What would the next step be?
Thanks, Pete
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