0-10V Spindle control issue

[AndyInPattaya]

Hi Khun Weerasak,

I'm setting up the spindle on my machine but I'm having problems with the Analog AO control, when I select 1000 RPM in mach 4 and start the spindle, it accelerates up to full speed. I measured the control voltage at the VFD (ACM, VI) and it was 11.67V.

I have programmed the VFD for external control (PD001, PD002) and selected 0-10V control (PD070).

Can you tell me what the problem might be?

Specs:
ESS + MB3
G-Penny 1.5kW water cooled spindle.
Huanyang HY01D523B VFD

Connections:
AG -> ACM
AO -> VI
RLA1 N.O. -> FOR
RLA2 N.O. -> REV
CM1,CM2 -> DCM

[Weerasak]

Hi AndyInPattaya,

I don't know what the maximum rpm of your spindle is. You need to set that value in the spindle tab in the Mach4 configuration.

Please check page 62 of the MB3 owner manual. It will show where it is.


or check out two VDOs on Youtube, which I produced a long time ago.

Code: [Select]

https://youtu.be/3moC7JytODI?si=ccMByapzB-kFT5pa&t=232

Code: [Select]

https://youtu.be/YYi5F2QiyQw?si=JEJiT_iooH6KkcjE&t=77

[AndyInPattaya]

The max RPM for the spindle is 24000.

I set up the Mach 4 RPM configuration before I posted, I have also mapped the Spindle PWM to the AO output according to the MB3 manual.

[Weerasak]

Hi Andy,

So, we don't have a problem with the software setup.

In the next step, we are going to find out the route to the problem.

First, you need to disconnect AO from the VFD analog input. Next, you need to command the Mach4 to send out a PWM pulse to AnaSpeed (name of the MB3 PWM converter). For example enter S12000M3 in MDI and execute it, 5v should appear on voltmeter.

Then measure AO and AG with a voltmeter. If you get the proper voltage out of AnaSpeed, at this point, we can assume that the interference noise from the Huanyang VFD disrupts the AnaSpeed function.

If all the above is true, then we can put in a DIY noise filter to block the interference noise from the VFD

[AndyInPattaya]

I disconnected the AO, AG wires from the VFD and measured the output from the Anaspeed at various speed settings using the S...M3 MDI commands, here are the results:

STOP 5.2mV
250 -> 24.6V
500 -> 24.7V
1000 -> 24.92V
5000 -> 26.6V
6000 -> 27.02
10000 -> 28.7V
12000 -> 29.54

So it looks like 24V is being added to the output somehow, this is obviously not a wiring issue because there is no significant voltage at STOP.

FYI, I have two control enclosures; one contains all the AC components (PSU's, VFD, AUX relays), and the other contains the MB3 and stepper drivers. The cable between the MB3 and the VFD only carries the signals mentioned in my initial post, i.e. no 24V.

[Weerasak]

Hi Andy,

I have never encountered this kind of problem before, and I would like to investigate to see where the high voltage comes from. The dc2dc converter only gives +12vdc and -12vdc to the circuit.

Could you please send the board back? I will find out and fix it real soon.

I sent you my address in personal message. Please check.

[AndyInPattaya]

Hi, since I posted this afternoon, I've done some more digging and I've established it's not a problem with the MB3 board. I disconnected the AO, AG pins at the MB3 side and measured the output directly from the board and it's fine - 5.02V @12000 RPM.

However, there's something weird going on because both wires have continuity between the MB3 and the VFD and there is no crosstalk between the other wires in that cable! 

When I made up the cable, I made sure to have some spare conductors, so I'm going to rewire using two spares.

I'll get back to you with any updates.

[AndyInPattaya]

Okay, I finally figured out the problem; inside the AC enclosure I'd got two wires crossed on the back of the cable connector. These were the AO signal and one of the DCM connections for the direction, which explains why I got all those weird results from the tests. I've rebuilt the cable assemblies and double-checked all the connections.

Now the spindle works BUT it won't maintain speed. I'll get stuck into this problem tomorrow.

[Weerasak]

Thank you for the update,
It is normal if the last digital of the RPM swings up and down.

The length of the cable and path would let the noise get into the line as well.

Sometimes , if you put a small capacitor at the VFD terminal end  connect it between

ACM
VI

for example, value of cap is 0.1 uF to 0.47 uF, that would maintain the quality of signal.

[AndyInPattaya]

The nearest value I have (non-SMD) is a 1.0uF 50V electrolytic, and it hasn't made any difference.

When I run a S6000M3 command, the Anaspeed voltage is rock-steady at 2.5V, measured at the VFD. The speed change is not small - it's dropping down to maybe 50% of the program speed.

Is this a fragged VFD?

[AndyInPattaya]

Okay, a few updates since my last post.

1. I bought a new VFD (same model) and got it installed. This time I logged each step of the installation & setup to make sure I didn't make any mistakes.
2. I bought a new multimeter, the old one was inaccurate.

And I've got exactly the same problems as before.

I bought a 10k pot and wired it across the ACM, VI and 10V terminals and the VFD worked fine, the speed was constant.

So this made me think about the 0 - 10V interface cable, which I replaced with a 2x1.5mm2 shielded cable with a 1uF cap across the VFD terminals, but the problem was the same.

So there is obviously something wrong with the MB3 card - unless I missed something else?

[Weerasak]

I think Huanyang VFD generates high EMC noise in itself, and this noise is escaping everywhere that it connects to. For example, if you touch the machine frame and feel some kind of high voltage pass through your body to earth ground. In this case, you need to have a good grounding.

This EMC noise also tried to get into MB3 and caused instability on Anaspeed output. In this case, you need to block the EMC noise by placing a small noise filter or a simple DIY inductor between MB3 and Huanyang VFD.
AO --[inductor   ] --- VI
AG --[inductor   ] --- ACM


https://www.instructables.com/Inductors/