[kolias]

Yes you can use the FA and FB for coolant Pump fans Etc, these will not work to control On / Off of the VFD Drive, you need to have a separate Relay that is controlled by G540 Output 5

As far as I know the VFD FOR terminal or the G540 Output 5 has a relay because now when I ask Mach3 with M3S10000 it starts the spindle.

Regarding what I said in my last post I was wrong because the VFD starts the spindle when Mach3 and G540 are OFF.

Do you know why the VFD will start the spindle without any external command?

[mactec54]

As far as I know the VFD FOR terminal or the G540 Output 5 has a relay because now when I ask Mach3 with M3S10000 it starts the spindle.

Regarding what I said in my last post I was wrong because the VFD starts the spindle when Mach3 and G540 are OFF.

Do you know why the VFD will start the spindle without any external command?

When FOR and DCM are used it is just being Switched, so it appears that when the G540 is turned off, this switching is closed, causing the Spindle to start, when the G540 is not powered up. this is never a safe way to have it wired, that is why a Relay is better as it needs power to be switched On / OFF

[kolias]

When FOR and DCM are used it is just being Switched, so it appears that when the G540 is turned off, this switching is closed, causing the Spindle to start, when the G540 is not powered up. this is never a safe way to have it wired, that is why a Relay is better as it needs power to be switched On / OFF

Normally I first start the PC / Mach3, then switch ON the G540 and finally the VFD. Yesterday since I only wanted to change the VFD parameters I just switched ON the VFD and discovered that the spindle started on its own.

I attach here my wiring diagram for information which I made in Excel. I could not upload the .xlsx file so I snip it and perhaps it’s too small. If you want the file let me know how I can send it.

Al_The_Man helped me to complete the wiring and I remember we had a few alternatives one of them included 2 relays (one for the cooling water pump and the other for the FOR) but I ended up removing both relays. I’m not qualified enough to re install the relays, perhaps if Al is available I will be glad to do so.

Thanks Mastec54 for the great help

[Al_The_Man]

so it appears that when the G540 is turned off, this switching is closed, causing the Spindle to start, when the G540 is not powered up. this is never a safe way to have it wired

Wrong.!
See the Schematic.

The FOR mod is just an output from the G540 direct to the PLC input on the VFD FWD
When the G540 is off then there is no output, the output FET is off so you cannot get FWD in this condition,
The relay is still powered by the FET so the same would result if it were to switch the relay on when the G540 is off, the explanation does not make any sense!
The only possible way is if the FET is shorted, and if it is, it will do the same with the relay.
I am sure I sent you the Homann hook up using the 20AMP relay, which by the way, draws much more current than the direct hook up to VFD input.
Al.

[kolias]

Wrong.!
See the Schematic.

The FOR mod is just an output from the G540 direct to the PLC input on the VFD FWD
When the G540 is off then there is no output, the output FET is off so you cannot get FWD in this condition,
The relay is still powered by the FET so the same would result if it were to switch the relay on when the G540 is off, the explanation does not make any sense!
The only possible way is if the FET is shorted, and if it is, it will do the same with the relay.
I am sure I sent you the Homann hook up using the 20AMP relay, which by the way, draws much more current than the direct hook up to VFD input.
Al.

Thank you Al, the RS485 is shown on the diagram for reference only and it has been removed from the cnc. Yes you did send me the Homann hook up but at one point we were using the two Omron 24VDC relays which later we removed

Started the VFD again today with the Mach3 and G540 OFF
Not knowing if it will make a difference I change 3 parameters on the VFD to their default values
PD163 was 1 and changed to 0
PD164 was 1 and stayed 1
PD165 was 3 and changed to 0
After a few seconds the spindle started on its own and she run at about 7K RPM
Pressing the STOP on the VFD it stopped the spindle
Pressing the RUN on the VFD did nothing so I switched the VFD OFF

Switched the PC ON and got Mach3 going
Switched the G540, and now the cnc is working (all axes working)
Switched the VFD ON, the spindle did not run
On Mach3 I wrote M3S8000 and the spindle came alive at about 8K RPM

I wanted to play with more commands but I noticed no water flow on the spindle cooling and after inspection I found the plastic discharge nozzle in the water pump was broken (cheep Chinese plastic?). So I stopped all and went to find a new fitting to fix the pump.

Bottom line is it looks like all is working fine with the exception of the spindle running on its own when I only have the VFD ON (Mach3 and G540 OFF). I can live with this unless someone tells me it is wrong to operate the cnc as it is

[Al_The_Man]

So does it turn off when the G540 is powered?, which doesn't make sense, did you try it with a relay?
The output is an open drain FET 2n7000 which if you remove power is essentially open circuit.
Al.

[kolias]

So does it turn off when the G540 is powered?, which doesn't make sense, did you try it with a relay?
The output is an open drain FET 2n7000 which if you remove power is essentially open circuit.
Al.

My cnc has 3 ON/OFF switches which power ON/OFF the PC, the G540 and the VFD.

To run the cnc, I first power ON the PC and wait until Mach3 is loaded

Then I power ON the G540

Then I power ON the VFD

With the above sequence, when the VFD is powered ON the spindle is not running. To get the spindle running I have to use Mach3 to send a command to the VFD to start the spindle.

I’m happy with the above sequence unless there is something wrong I don’t see.

The spindle runs on its own ONLY when I start the VFD alone (the PC and G540 are OFF). Normally I never do that because there is no need to have the VFD running alone

[Al_The_Man]

Something is odd as even if you had a start command there should also be no analogue signal?
What rpm does the spindle run at when you power up that way?
Al.

[kolias]

It depends what I ask Mach3 to do

Like this morning I ask M3S8000 and the spindle started at 8K RPM, then I ask M5 and the spindle stopped

I didn’t try this morning any other speeds because I had to fix the cooling water pump but in the past I got it going up to 22K RPM

As far as I know the VFD / Spindle runs good except when I only have the VFD ON and the spindle runs on its own for no reason (at low RPM). I have no problem with that since I have no reason to run the VFD alone (means with Mach3 and G540 OFF)

[kolias]

Cooling water pump works fine today so I tried various spindle speeds using Mach3 and all working well with a +2-4% speed variation from what I asked and what I measure with my handheld tach. For my needs that’s accurate enough

Pressing the E-Stop the spindle and all axes stop instantly
Asking Mach3 for M5, only spindle stops within a few seconds

[mactec54]

It depends what I ask Mach3 to do

Like this morning I ask M3S8000 and the spindle started at 8K RPM, then I ask M5 and the spindle stopped

I didn’t try this morning any other speeds because I had to fix the cooling water pump but in the past I got it going up to 22K RPM

As far as I know the VFD / Spindle runs good except when I only have the VFD ON and the spindle runs on its own for no reason (at low RPM). I have no problem with that since I have no reason to run the VFD alone (means with Mach3 and G540 OFF)

If you ask M5 then the Spindle should Stop

[mactec54]

Wrong.!
See the Schematic.

The FOR mod is just an output from the G540 direct to the PLC input on the VFD FWD
When the G540 is off then there is no output, the output FET is off so you cannot get FWD in this condition,
The relay is still powered by the FET so the same would result if it were to switch the relay on when the G540 is off, the explanation does not make any sense!
The only possible way is if the FET is shorted, and if it is, it will do the same with the relay.
I am sure I sent you the Homann hook up using the 20AMP relay, which by the way, draws much more current than the direct hook up to VFD input.
Al.

No it is not wrong you are so sure of your self, with no correct solution, this is the reason I told kolias to remove the output 5 connection, to try it without that connection, this would tell you who is right, the only way the VFD will start when connected like this is if the is a connection between the FOR and DCM, the FET has shorted, that is why I never recommend anyone to wire the G540 this way, as many have failed from your advice to wire them this way

[kolias]

If you ask M5 then the Spindle should Stop

I understand M5 will stop the spindle but the problem is why the spindle starts when I power up the VFD alone. In any case as mentioned earlier I can live with that because normally I always start Mach3 and G540 before I start the VFD

[mactec54]

I understand M5 will stop the spindle but the problem is why the spindle starts when I power up the VFD alone. In any case as mentioned earlier I can live with that because normally I always start Mach3 and G540 before I start the VFD

I said what to try, and then we would know for sure what has happened to the G540, disconnect the wire to FOR and see if the VFD starts up if it does not then we know the FET in the G540 has closed when it's power is off, very simple test

[Al_The_Man]

I understand M5 will stop the spindle but the problem is why the spindle starts when I power up the VFD alone. In any case as mentioned earlier I can live with that because normally I always start Mach3 and G540 before I start the VFD

According to the circuit, the FET is an open drain, and with the power off the unit the FET would normally have to be shorted to start the VFD,
Because if it conducts when G540 is off and starts the VFD, then the same should occur with a relay.
Possibly something else going on there.
Al.

- - - Updated - - -

[kolias]

I said what to try, and then we would know for sure what has happened to the G540, disconnect the wire to FOR and see if the VFD starts up if it does not then we know the FET in the G540 has closed when it's power is off, very simple test

Ok Mastec54, give me about 1 hour and I will post back the results.

[kolias]

I disconnected the FOR wire from the VFD, started the VFD alone (Mach3 and G540 are OFF), spindle did not start

What does it mean?

[Al_The_Man]

Did you see if the same thing occurs with a relay?
What is the analogue signal from the G540 when you do that.
Al.

[Al_The_Man]

Looking over the schematic again, I think I see what is happening, there is one condition it can happen in, it is because there is a signal out of the PC parallel port, even when the G540 is powered down and Mach is shut down.
But regardless, if the system is powered down and the VFD left on it is not a safe situation, Period, this is never done in and industrial environment and should not be done in a DIY one either.
If a proper approved method of power down control is done, this condition would never happen.
Al.

[kolias]

Looking over the schematic again, I think I see what is happening, there is one condition it can happen in, it is because there is a signal out of the PC parallel port, even when the G540 is powered down and Mach is shut down.
But regardless, if the system is powered down and the VFD left on it is not a safe situation, Period, this is never done in and industrial environment and should not be done in a DIY one either.
If a proper approved method of power down control is done, this condition would never happen.
Al.

I dont understand Al what’s going on but the VFD is never left ON (without the PC and G540) since there is no reason to leave it ON. After a job is done the shut down order is:
Switch the VFD OFF
Switch the G540 OFF
Close Mach3
Switch the PC OFF

When I had the relays installed I never got the cnc going because at that time the wiring was in progress so I don’t know if this situation occurred.

However I do remember the following: when the time came to start the cnc for the first time I started the VFD alone to program it based on the parameters Mastec54 gave me. I remember this because I never used a VFD before and I was afraid to have the G540 / Mach3 ON at the same time. During this time I don’t remember the spindle was ON.

I have also changed the following parameters:

PD046 My setting = 04 (Stop), Default value = 14 (Reset)
PD047 My setting = 13 (E-stop), Default value = 22 (High Speed)
PD052 My setting = 01 (Run), Default value = 03 (Fault indication)

Is it possible that a parameter on the VFD creates this problem?