Hi Whenever I connect my z probe, the light goes on on the Blackbox. I see from a search that some others have struck this before, but I am not sure what to do. I have a Workeee 1010 Blackbox. Chinese spindle All of these are earthed. When I use a laptop, everything works as it should. Laptops have a 2 pin plug on their brick and are not earthed. When I connect a desktop and monitor (both earthed) via usb cable to the Blackbox the z probe light comes on. At the same time, the spindle suddenly is connected to the Blackbox ground (checked using a limit switch ground). If I disconnect the usb cable, everything reverts to correct operation. Any idea how I can fix things so I can use a desktop computer rather than reverting to a laptop? TIA Gary
Somehow incorrectly earthed. Allowing AC Earth to be joined to DC GND (which it should not, one is mains, the other is in the DC domain). See XYZ Probe Plus with VFDs and other ground-loop inducing components But basically, find the short between EARTH and GND, fix that before it causes permanent damage Issue may be inside the desktop PC too, a black DC GND touching metal case shorting to EARTH, or a PSU gone bad with insufficient DC/AC isolation
Hi, I have been unable to find any shorts between earth and ground. I first Idisconnected all limit switches and the problem is still there. I then disconnected everything from the blackbox apart from the probe and the problem is still there. The spindle terminal 4 is earthed both to the VFD and to the spindle body. The VFD is not connected to the Blackbox. The power supply for the Blackbox is earthed The PC is earthed - continuity tests on both my desktop pcs show that mains earth is connected to the motherboard usb outlets so I assume this is at it should be. The power supplies in both PC's seem to be fine. All devices are plugged in to the same power strip and mains earthed via it. The error is "Alarm 4 Probe fail. The probe is not in the expected initial state before starting probe cycle, where G38.2 and G38.3 is not triggered and G38.4 and G38.5 is triggered" If I disconnect pin 4 then all is well, but the spindle is then not earthed and is dangerous. Can't find any problem? Any other suggestions? I read all the link you included. Is the Blackbox not suited to this? Have to go back to a laptop which is not mains earthed? I guess I could invert the connector wires on the z probe, but wouldn't that mean that the mains earth and ground were still linked? cheers Gary EDIT: would a USB opto isolator from PC to Blackbox fix the issue?
It would get you working by hiding the fault - but at the end of the day there is still leakage between Earth and GND. Your choice.
I have to admit I'm at a loss as to where the problem could be. All connections to the black box were removed except for the probe. As long as the VFD i and the PC are connected the problem exists. Tried 2 different PC's, had the VFD wiring checked by my neighbor who is an electrical engineer, and neither of us has a clue as to where the problem could exist except if something is wrong in the Blackbox itself........ I don't have much hair left so tearing much more out is not an option!!! Gary
Could also be: If the magnet doesn't touch the spindle, what does the Troubleshooting tab indicate for the Probe input? And then when you magnet touches the spindle? I'm sure you'll notice it changing from OFF to ON once it touches the spindle... All that detects is current flowing from GND to the SIG input via the Spindle body, somehow finding a route back to DC GND (Which should be seperate sections of the circuit normally, is somehow shorted together via the spindle/vfd/pc/wiring/othermistakes) Have him do an isolation test between DC GND and AC EARTH - he'll know what that means - the PSU should Isolate the AC MAINS and EARTH from the DC 24 and GND side. We have hundreds of desktop users - and many have been down the road of yours before - getting in there with a multimeter and finding what is accidentally connecting DC GND back to AC EARTH and eliminating that fault is the way to go Yes there are workarounds, but someday when your dryer in the basement has an issue and shorts LIVE to the chassis, the EARTH rail of your whole house is momentarilly at 110v, until the GFCI trips. In that time, you've fried the BlackBox input, Computer and the VFD probably... That's why its important to find... You do not mix Mains side voltages (Including Earths and Neutrals) with the other side of the DC domain (24V and GND)
Will keep trying - will report back - may take a couple of days as we are in lockdown now here... Gary
If the magnet doesn't touch the spindle, what does the Troubleshooting tab indicate for the Probe input? And then when you magnet touches the spindle? I'm sure you'll notice it changing from OFF to ON once it touches the spindle... All that detects is current flowing from GND to the SIG input via the Spindle body, somehow finding a route back to DC GND (Which should be seperate sections of the circuit normally, is somehow shorted together via the spindle/vfd/pc/wiring/othermistakes) Not using the xyz probe, only a simple z probe... Gary
Problem successfully diagnosed: I had tried two identical PC's both over 10 years old with the same motherboards. Both caused the problem. A third PC worked fine, so that meant the problem had to be the first two PC's. No matter what cables I unplugged I still had the usb connection to earth. I finally dismounted the motherboard and removed it from the PC - even with all power cables and accessories plugged in the problem disappeared. Examining things closely I found that the mounting holes (that screw the board to the case) had continuity to the all the motherboard ports. Thus when the motherboard was attached to the metal standoffs by metal screws, there was 5 volts being fed to earth causing the problem. These 2 pc's should have been assembled with plastic standoffs and screws to isolate the motherboard, but were not. My fault for buying cheap!! They have been in this state for 10 years, and I guess I'm lucky that they did not fry the peripherals. Hope this is clear? Thhanks Gary
Winner winner! Immense respect for sticking with it and doing the right thing glad you found it and that is one to note for the future if others have the same issue. Good find!
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