VFD interference problem

[eurikain]

I have, really, there's only the drivers, 5V and 70V PSU wired. The VFD is powered completely separately from the control cabinet. It's a different wall socket. Yes, it could be the mains. I need to call my local electronics store for help, I'm really lost now ^^. Can't deal with this myself.

[Clive S]

I have, really, there's only the drivers, 5V and 70V PSU wired. The VFD is powered completely separately from the control cabinet. It's a different wall socket. Yes, it could be the mains. I need to call my local electronics store for help, I'm really lost now ^^. Can't deal with this myself.

Does your building have an earth supplied by the electric company or do you use earth rods in the ground. Are you still using the plastic control box? Pictures would help.

When you say the motors move a few steps when you turn on the vfd are they enabled and the motors locked when this happens?

[cropwell]

Does your building have an earth supplied by the electric company or do you use earth rods in the ground. Are you still using the plastic control box? Pictures would help.

When you say the motors move a few steps when you turn on the vfd are they enabled and the motors locked when this happens?

I don't know the electrical safety regulations in Belgium, but I would guess they are much the same as in UK. I would expect the earth to be strapped to the plumbing although this is not necessarily a good ground contact with plastic pipes .

[JAZZCNC]

Rob is correct that you shoudln't be spending money without sorting the problem. While the Cslabs are good with noise this doesn't mean it will cure your problem. The noise could be being picked up in number of places, the signal cables to drives for instance which are between Cslabs and Drives.

You NEED to find and remove the noise at the SOURCE. Buy mains Filter for both the Control box and the VFD before buying anything else.

[eurikain]

Yes, the building earth goes to the electric company I believe. Standard setup here. I am actually not using any box anymore, it's all out of the box, screwed on a fireproof plate (not metal). I am sorry I haven't posted pictures. Here it is:

The X motor plates have been unmounted to prevent the gantry from twisting. The fireproof board is out of the box for easy access and testing.


All relays are not wired, there is no e-stop, no reset button, no contactor, not fans, no switches (only a switch on the power cord extension), no 24V power supply (Earth and Neutral are daisy chained with the 5V PSU, but there is no Load going to it as you can see).


So, here is what happens:
1. drivers powered, Mach3 in reset mode, motors disabled, VFD powered, spindle off
2. click reset in mach3, motors are powered, enabled and locked
3. I can jog fine on each axis
4. press RUN on the VFD, spindle starts spinning right away. half a second after pressing RUN, I can feel (with my hand) and hear the motors move a few steps (ike 2-5 I would judge by feeling). Obviously I can't put my hands on all motors simultaneously, so I try one by one (the VFD is wired separately so I can carry it around with me).
5. press STOP on the VFD, same thing, right before the spindle stops spinning (so I would say in the lower frequency, around 500/1000 RPM), the motors move a few steps.

There are two parameters to the noise:
1. the time offset between the moment I press RUN or STOP. I guess this depends on the time it takes to get to the problematic frequency.
2. the number of uncommanded steps the motors move

If I press RUN, then wait until the spindle reaches the desired speed (100Hz), then press STOP, wait until it stops, and repeat this process a few times, I would say the problem occurs 7 times out of 10. The number of uncommanded steps and the time offset are always random.

Hope you can see things better now :)

Cheers,
G.

[cropwell]

I can see one problem straight away. You have no main power to the BoB. In the (invisible) picture below the two middle connectors on the right are the main power (12 - 24v) for the BoB electronics. Without that you will get all sorts of random effects.

I tried to copy and paste from the pdf of the BoB manual, but it didnt work - anyway OP has BoB manual.

[eurikain]

I can see one problem straight away. You have no main power to the BoB. In the (invisible) picture below the two middle connectors are the main power (12 - 24v) for the BoB electronics. Without that you will get all sorts of random effects.

I know the pins you are talking about Rob :) Even when the BOB is powered by the 24V PSU, there is still noise :(

[routercnc]

I seem to remember that you can also power it through the USB socket. You could try this from the PC, if this works then longer term use a USB plug and lead but cut the cables, identify the power supply cable and wire it to an external 5V supply.

[eurikain]

I seem to remember that you can also power it through the USB socket. You could try this from the PC, if this works then longer term use a USB plug and lead but cut the cables, identify the power supply cable and wire it to an external 5V supply.

Yes, that's right, but there are two terminals made to replace the USB port, and I'm currently using them:

[cropwell]

I seem to remember that you can also power it through the USB socket. You could try this from the PC, if this works then longer term use a USB plug and lead but cut the cables, identify the power supply cable and wire it to an external 5V supply.

On the BoB OP is using the USB socket is connected by tracks on the board to the PC 5v and PC GND, so the USB socket is not needed.
But those shielded cables won't do much good if they are not earthed at one end.