[Al_The_Man]

I am getting confused, you said previously that the VFD would start when the G540 and Mach were off, now you say it is never left ON?
As I said, I do see a possible way if the VFD is ON and Mach and G540 is off, but you should never have this condition.
The VFD and all servo's/steppers should be disabled from operation until the system has booted up and is ready and enabled by Mach.
If Mach is not running, the power to the VFD should be OFF.
Al..

[mactec54]

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?

They should all be at the Default setting, but they will have no affect on this

[mactec54]

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?

It means that the G540 output it's switching is closed, when the power is off, this may be a bad FET, but if it is working when the Power is On then it may be by design, and how it has been configured in the G540

[Al_The_Man]

No, the FET does not have to be shorted, it does not get any power from the G540 direct, the input to the Opto switching the FET gate comes direct from the Printer port, if there is power to the FET drain via say the VFD 24v PLC and if the P.P. has a high on it when Mach is down the FET will switch on, but regardless, if normal standards are observed as in correct procedures and using for example the watch-dog/charge pump timer in Mach to trigger the proper E-stop or mandatory shut down procedures it can and should Never happen.
Al.

[kolias]

Lets clarify something Al.

Perhaps I didn’t explain properly but the VFD never starts on its own, what I mean is when I push the power button to start the VFD after a few seconds the SPINDLE will start to turn at low RPM (about 7K RPM) and this only happens when I have the PC and G540 OFF. Normally this situation never happens because I ALWAYS start first the PC and load Mach3, then I start the G540 and last I start the VFD.

There is no reason to push the power button and start the VFD if Mach3 / G540 are not loaded.

So when you say

“The VFD and all servo's/steppers should be disabled from operation until the system has booted up and is ready and enabled by Mach. If Mach is not running, the power to the VFD should be OFF.”

That’s exactly what I always do.

Mastec54 I will change the 3 parameters to their default values

[Al_The_Man]

Lets clarify something Al.

Perhaps I didn’t explain properly but the VFD never starts on its own, what I mean is when I push the power button to start the VFD after a few seconds the SPINDLE will start to turn at low RPM (about 7K RPM) and this only happens when I have the PC and G540 OFF. Normally this situation never happens because I ALWAYS start first the PC and load Mach3,
That’s exactly what I always do.

Then I can see no problem?
The bottom line is that it should not be up to you to remember the sequence, it should be built into the system that in the event you perform the wrong sequence, nothing untoward will happen.
This is exactly the reason for all the protection means I have outlined.
IOW it should NEVER be up to the operator to remember a certain sequence in order to power up in a safe manner.
Al.

[kolias]

Thank you Al, I understand

I will remember that if I build another one

[mactec54]

Then I can see no problem?
The bottom line is that it should not be up to you to remember the sequence, it should be built into the system that in the event you perform the wrong sequence, nothing untoward will happen.
This is exactly the reason for all the protection means I have outlined.
IOW it should NEVER be up to the operator to remember a certain sequence in order to power up in a safe manner.
Al.

I agree

The VFD should not be able to be started no matter how the power up is done by design. there is a problem with this because it can be started, either wiring or a design problem, the FET should not be able to get any power until everything has been power up, and then turned on by a control command

[Al_The_Man]

I agree

The VFD should not be able to be started no matter how the power up is done by design. there is a problem with this because it can be started, either wiring or a design problem, the FET should not be able to get any power until everything has been power up, and then turned on by a control command

This is why it takes either knowledge of the total system or obtain help here in order to wire safely.
The problem is enhanced by those with limited knowledge in putting together a system with separate sourced component pieces and the main reason they come to sites like this that attempt to steer them in the right direction.
There is no problem with the individual items, Mach/PC, G540, VFD, but when pieces of a system are obtained from different sources and mated together there is potential for things like this to go wrong, but I stand by my previous statement that ANY system, whether Industrial or DIY should conform to the safety suggestions and regulations laid out in such as NFPA79 and NEC/CEC and EU that pertains to Emergency stops and system shut down procedure.
It would be inconceivable for any Industrial package to have a shut down of the main controller and leave any motorized parts of the system powered up and running.
The problem in this case is having the VFD powered and ready when the Mach S/W is shut down the P.Port changes state. If correct wiring procedure is carried out cannot happen.
Mach does offer a simple solution that not all follow, namely the watch-dog/Charge Pump time out to shut off any powered device when Mach is closed.
Al.