Need Help!- G540 & VFD

[PEU]

I have this VFD schematic for external control via 0-10v:



Should I use VFD Output (pos8) and VFD GND (pos7) and leave VFD +10V (pos9) unconnected?

Thanks!

[Fastest1]

ANALOG OUTPUT: This is a 0V to +10V opto-isolated analog output intended for use with VFD drives. VFD OUT goes to 0VDC while the G540 is disabled. Connect VFD GND, VFD OUT and VFD +10V to the VFD drive inputs. Make sure the VFD drive positive voltage does not exceed +12VDC. Do not short VFD OUT to any other terminal. Do not reverse polarity to VFD GND and VFD +10V or the G540 may be damaged.

[PEU]

Yes I did read the manual before asking, thankyouverymuch...

I will use your quote of it in italics to add my comments


ANALOG OUTPUT: This is a 0V to +10V opto-isolated analog output intended for use with VFD drives. OK, this is an output

VFD OUT goes to 0VDC while the G540 is disabled. Connect VFD GND, VFD OUT and VFD +10V to the VFD drive inputs. OK, all are outputs

Make sure the VFD drive positive voltage does not exceed +12VDC. This I don't understand as it implies the VFD has some sort of 10V output that goes to the G540 outputs, not clear at all

Do not short VFD OUT to any other terminal. Do not reverse polarity to VFD GND and VFD +10V or the G540 may be damaged. Also not clear, so the VFD should provide 10V? I Think I'm missing something obvious, but cannot figure out what.

The G540 manual is very brief in explaining this, that's why I posted.

If you want to peek at the VFD manual, I found the english version of the it here (the one I have is in spanish) I have the 0.75kw version monophase/singlephase and as noted in printed page 30 this model does not have the +10V terminal

Thanks!


Pablo

[Al_The_Man]

I have not used either product, but it would appear to me that the G540 expects the VFD to supply the analogue power of 12vdc max.
The model in your case seems to supply 24v for an external analogue supply.
If I am correct, you should be able to use the 0-10v connection, but will have to provide an external 10v to the G540.
This would be my interpretation.
Al.

[PEU]

Thanks Al, in this thread Mariss says it needs an external power supply, Im not sure where to feed these 12v, should I use the OUTPUT labeled 10V as an INPUT for this voltage? you see where my confusion comes from right?


Thanks!

[Al_The_Man]

The 10v supply common would go to the VFD COM and the Gecko VFD GND (7)
the +10v would go to Gecko (9).
The VFD AI2 would go to Gecko (8).
At least that would be the way I interpret it.
The VFD just needs two connections, common and AI2.
Al.

[PEU]

I understand it the same way Al. Thanks!

I think some clarification regarding this would improve the G540 user manual.


Pablo

[Fastest1]

Pablo, I wasnt trying to offend just making sure that page was accessible, just in case. I have been guilty of not understanding and or not reading something before. Personally I am glad Al chimed in as I will have these connection issues soon and it answered questions I hadnt even asked myself yet. The more I play with these products the more it seems we need about 5 different power supplies by the time you figure limits, probes, vfd's, etc.

[PEU]

Originally Posted by Fastest1 Pablo, I wasnt trying to offend just making sure that page was accessible, just in case. I have been guilty of not understanding and or not reading something before. Personally I am glad Al chimed in as I will have these connection issues soon and it answered questions I hadnt even asked myself yet. The more I play with these products the more it seems we need about 5 different power supplies by the time you figure limits, probes, vfd's, etc.

No offense taken (check the smile I added)

You are right, I need to add an external supply for the VFD reference voltage because the VFD I use does not have a 10V reference output, also one needs to add an extra supply for the relays and for the inductive sensor I use for the spindle index. Luckily the 10V input tolerates 12V (per the manual) so I can use the same supply for all these.

It would be great if the G540 could supply the reference voltage derived from the motors supply, maybe a little buck switching power supply could do the trick.




Pablo

[Al_The_Man]

For the G540 10v supply in the absence of it being supplied from the VFD, what I would try in this case is to determine the current requirement of the G540 analogue supply by feeding it temporarily with a separate 10v supply and read the current draw, I very much suspect it is going to be fairly constant.
In this case I would use a series resistor fed off the VFD 24v dc followed by a 10v zener and small electrolytic to COM.
The resistor value would be based on the required voltage drop from 24v to 10v less 10% or a lower value if neccessary, avoiding too low a value requiring a high wattage resistor.
This circuit is high impedance so I would not expect to see a high degree of current or current fluctuation from the analogue feed.
Al.

[Mariss Freimanis]

PEU,

<i>"It would be great if the G540 could supply the reference voltage derived from the motors supply."</i>

When the G540 was designed, the VFD section was meant to replace the remote speed control potentiometer. My understanding was most VFD drives have that option. A 5K potentiometer is specified and it has 10VDC across it.

The G540 VFD section was designed using a 10VDC @ 2mA "budget" (10V across 5K is 2mA).

The G540 'VFD+10V' terminal 9 and the 'VFD GND' terminal 7 go to the VFD drive potentiometer +10VDC and GND connections respectively. The G540 'VFD OUT' terminal 8 goes to the potentiometer wiper input of the VFD drive.

It's unlikely we'll add an internal DC-DC converter to the G540 because there is too little room on the G540 motherboard to accommodate one. Secondly, we are putting our efforts into the next major transformation of this product which will be called the GM540.

'GM' stands for 'GeckoMotion' which means the same package (4-axis 3.5A, 50VDC) will contain a full 4-axis vector motion controller (PIC24FJ 16-bit processor and a 30K gate FPGA). We will also eliminate the DB-9 connectors and use 3.5mm modular screw-terminal type Phoenix connectors. Communication will be RS-485 and no, it won't work with Mach3.

Mariss

[Al_The_Man]

Originally Posted by Mariss Freimanis The G540 'VFD+10V' terminal 9 and the 'VFD GND' terminal 7 go to the VFD drive potentiometer +10VDC and GND connections respectively. The G540 'VFD OUT' terminal 8 goes to the potentiometer wiper input of the VFD drive. Mariss

Mariss, apparently this VFD does not supply +10v for the Pot.
It can be set for 24vdc pot supply or just analogue input and com.
See configuration post #1.
Al.