[reg.miller]

An inductor/choke between the Motor and VFD Drive only helps to protect the Motor, an Inductor or Filter before the VFD help to protect the VFD Drive

An inductor between the Motor and VFD is not normally used for short cable length, but a input power filter or inductor is more important

I thought an input filter was to prevent noise getting back onto the supply.

[Al_The_Man]

An inductor/choke between the Motor and VFD Drive only helps to protect the Motor, an Inductor or Filter before the VFD help to protect the VFD Drive

An inductor between the Motor and VFD is not normally used for short cable length, but a input power filter or inductor is more important

The 3ph inductor protects both motor and VFD, at least the technical bulletins I have ever received from the leading international VFD manufacturers (Not Chinese!) that I have used, Virtually the same reason there is a choke fitted to DC outputs of low frequency DC motor controllers.
The filter on the input is mainly for power factor protection and the supply Before the VFD.
I just attended a 2 day seminar by the Provincial Electrical Hydro Service engineers here on the very subject.
In all the years I have been installing these system I have never yet used a Input filter/inductor, to my knowledge, there has never been a failure by any of my installations using the inductor only on the VFD output.

I thought an input filter was to prevent noise getting back onto the supply.

True!
Plus P.F.Corr..
.

[mactec54]

The 3ph inductor protects both motor and VFD, at least the technical bulletins I have ever received from the leading international VFD manufacturers (Not Chinese!) that I have used, Virtually the same reason there is a choke fitted to DC outputs of low frequency DC motor controllers.
The filter on the input is mainly for power factor protection and the supply Before the VFD.
I just attended a 2 day seminar by the Provincial Electrical Hydro Service engineers here on the very subject.
In all the years I have been installing these system I have never yet used a Input filter/inductor, to my knowledge, there has never been a failure by any of my installations using the inductor only on the VFD output.

.

Most VFD Drive manufactures will tell you different, so i'm not sure what you are looking at, it is easy to find what I said is correct

[mactec54]

I thought an input filter was to prevent noise getting back onto the supply.

Input line reactors protect the VFD drive from transient overvoltage conditions typically caused by utility capacitor switching. Input line reactors protect the front end electronics and also reduce the harmonics associated with AC drives, and are recommended for all installations.

Output line (load) reactors protect the back end of the VFD Drive electronics and the motor insulation against AC drive short circuits and IGBT reflective wave damage, and also allow the motor to run cooler by “smoothing” the motor current waveform. They are recommended for operating “non-inverter-duty” motors, and for any motors where the length of wiring between the AC drive and motor exceeds 75 feet.

There are many examples like this PDF

[jgomez]

Hi all,

I need help , my Inverter is leakage 110v to case of spindle, this cause Z axis to move alone and not stop until cut off motors

Anybody know what voltage in pins UVW ?, in my inverter have 110 oscilating to 150v in each pin

My inverter model is 2.2Kw 220V monofasic

[mactec54]

Hi all,

I need help , my Inverter is leakage 110v to case of spindle, this cause Z axis to move alone and not stop until cut off motors

Anybody know what voltage in pins UVW ?, in my inverter have 110 oscilating to 150v in each pin

My inverter model is 2.2Kw 220V monofasic

If you have voltage to the spindle body then you have a short, check that the spindle plug wires are not touching the outside of the plug

With the power disconnected check the spindle plug Pin1 to spindle body and the same for the other pins, if there is no short at this point then it is in your plug wiring that you attach to the spindle

You can not measure the output voltage of the VFD with a regular multimeter you can damage the VFD Drive if you do this

[jgomez]

Hi Mactec54,

Thanks for your reply, in pins UVW not have any short over spindle case, I use an Fluke True RMS to measures voltage in terminals.

But when I start machining aluminum, from scratch the Z axis begins to descend without stopping I placing the multimeter between the ground of the Inverter X Spindle case I note the voltage of 100V

[skrubol]

You need to ground your spindle case. At the very least a wire at least the size of the UVW wires directly from the case of the spindle motor to a good ground (preferably a star ground.)
That may still not take care of your noise problem, and it may cause other problems to show themselves, but at least it will be safer, and is a first step to fixing your noise problem.

[jgomez]

I have good ground bar with 2.4m and use 6mm wire to this is in Inverter pin marked as Ground.

The trouble is intermitent, some times i use machine without any problem, but when see this, i have 100 / 110V between spindle case and inverter ground

Any chance of my Inverter or spindle damaged ?

[skrubol]

That's good that your inverter is grounded. Your spindle must also be grounded though. As is right now, a single wiring fault could put lethal voltage on the case of your spindle.

[jgomez]

Many thanks skrubol,

Later i do more test in my machine, but i do not undestand why this defect are intermitent

[skrubol]

If you mean the Z axis movement, it's probably due to noise, and lots of external factors can influence that. It could come down to the position of the axis, where you're standing, the humidity, temperature, etc. Proper grounding and shielding are the way to reduce emitted noise (From the spindle and motors,) and reduce susceptibility to noise (signal wires to motor drives, and sensors/switches.)

[jgomez]

I do not have any end stop in XYZ axis, machine work fine milling alluminum but while see the trouble, my Z axis dont stop move, in this case while Z axis move, i put multimeter between spindle case X ground in inverter and see 100/110V.

[mactec54]

I do not have any end stop in XYZ axis, machine work fine milling alluminum but while see the trouble, my Z axis dont stop move, in this case while Z axis move, i put multimeter between spindle case X ground in inverter and see 100/110V.

Do you have a shielded cable from the VFD to the Spindle

It can be quite normal to have a Ground voltage when the VFD Drive is running, yours does seem a little high for one of these spindles, the Rotor in the spindle will have a voltage that has to go to ground sometimes this can be quite high like you are seeing, this happens with all VFD Driven AC motors, that is why correct Grounding and Shielded Cables must be used and correctly terminated, post some photos of your wiring I may be able to see if there are any problems

[mactec54]

You need to ground your spindle case. At the very least a wire at least the size of the UVW wires directly from the case of the spindle motor to a good ground (preferably a star ground.)
That may still not take care of your noise problem, and it may cause other problems to show themselves, but at least it will be safer, and is a first step to fixing your noise problem.

You can not do it this way by adding a Ground wire, if you added a Ground wire like this then it becomes an antenna

[skrubol]

You can not do it this way by adding a Ground wire, if you added a Ground wire like this then it becomes an antenna

Yes, but an antenna won't kill you (keep it out of thunder storms,) an ungrounded spindle can.
If the ground is run close to the UVW wires it will help with noise as well. Not as good as a jacketed, shielded cable, but better than nothing.

[jgomez]

I do not have shielded cable from VFD to Spindle, you can sugest one for me ?.

And if possible, you can schematic how to do wire all cable from VFD > Gronding > Spindle

In Brazil not easy bought shielded cables with good quality

[Delloman]

https://www.wireandcableyourway.com/...ply-cable.html

[Al_The_Man]

I do not have shielded cable from VFD to Spindle, you can sugest one for me ?.
And if possible, you can schematic how to do wire all cable from VFD > Gronding > Spindle
In Brazil not easy bought shielded cables with good quality

Is this a Mill, i.e. moving XY table with stationary spindle?
Al.

[jgomez]

Thnaks, But i am in Brazil, and very spensive to buy for in this location

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Is this a Mill, i.e. moving XY table with stationary spindle?
Al.

Not, spindle move with gantry X/Y