wireless remote for inverter

[shipto]

I have a 2.2kw inverter in my shop which currently is running my homemade mill, this previously used a 0.8kw or thereabout but when I was offered this inverter at work I came away with a portion of the bosses arm  and being daft I then gave the smaller one to my mate for his hobbymat lathe.
Now also from work I have a 2.2kw motor which I am going to fit to my Harrison lathe. The reason being I need to be able to run the lathe in reverse to use a die head to cut some left handed threads.
I have a barrel switch? which can direct the inverter output between the lathe and the mill but the controls for the inverter are wired to a box with some magnets to mount it where I want it but I would prefer some kind of wireless solution if possible. There are 6 wires in total FORWARD-GND-REVERSE and 3 for the speed pot.
So I am firstly asking if I should even switch this inverter between the two machines, I cant imagine it would cause a problem but maybe other can see one.
secondly I am looking for suggestions for a wireless remote to control the inverter.

[philf]

.............
I have a barrel switch? which can direct the inverter output between the lathe and the mill but the controls for the inverter are wired to a box with some magnets to mount it where I want it but I would prefer some kind of wireless solution if possible. There are 6 wires in total FORWARD-GND-REVERSE and 3 for the speed pot.
So I am firstly asking if I should even switch this inverter between the two machines, I cant imagine it would cause a problem but maybe other can see one.
secondly I am looking for suggestions for a wireless remote to control the inverter.

Shipto,

Whatever you do don't operate the switch if the inverter is running one of the machines. It would probably better to power the inverter off.

I don't know how you could operate the inverter remotely - there are 3 channel remote relay units but I don't think I'd be comfortable using one for something as potentially damaging as a lathe or mill.

Phil.

[shipto]

Shipto,

Whatever you do don't operate the switch if the inverter is running one of the machines. It would probably better to power the inverter off.

I don't know how you could operate the inverter remotely - there are 3 channel remote relay units but I don't think I'd be comfortable using one for something as potentially damaging as a lathe or mill.

Phil.

Yeah already figured that would probably be a bad idea but there is a bit of safety in the barrel switch however as there is 4 positions with the two middle positions being off so its not like you could switch from one to the other by accident.

[djc]

Yeah already figured that would probably be a bad idea but there is a bit of safety in the barrel switch

It is not so much a safety issue, more it is not recommended from an electrical point of view ever to switch a VFD downstream of its output. On older VFD's this could lead to them being damaged. I think it is a lot less of a problem on current generation ones, but you have to ask yourself if you feel lucky today.

The radio-controlled switching might be less of a worry if you had two E-stop buttons hard wired in series between the two machines.

For simple switching, one radio-switched channel per item being switched is easy, but the potentiometer is more difficult. Something like this would do, assuming the pot value is suitable, but it is only a single switched channel so you could not do reverse:

https://www.amazon.co.uk/perfk-Infrared-Potentiometer-Integrated-Circuits/dp/B07LB2WXQX

Put a plug and socket on the existing machine so the control box is removable. Run wires to the new machine with a duplicate socket. Then you can carry the control box between machines.

[David Jupp]

Some inverters have wireless remote options - (mainly for commissioning/testing?)

For example Lenze i500 series have a WiFi adapter available and an Android/iOS app ('Smart Keypad').

Wouldn't surprise me if other brands have similar options...

If you do go wireless, make sure to keep hard wired e-stops near both machines. 

[shipto]

Put a plug and socket on the existing machine so the control box is removable. Run wires to the new machine with a duplicate socket. Then you can carry the control box between machines.

That sounds like a good idea  it would also allow me to do what I was planning to stop lathe reversing when in top gear.

[JHovel]

Just for your information: reversing a motor with a VFD (inverter) is not a problem. It will not harm either the VFD or the motor, because the VFD has enough smarts to stop the motor first (hopefully you have it set to slow down in a controlled fashion) and restart it in the opposite direction according to it's set acceleration curve. I've been doing that with VFDs and even very old motors for more than 25years.
The only time that's not a good idea is if you have an emergency hard stop programmed (and use the appropriate external braking resistor to do that). But then, you would presumably have a separate emergency stop button for that function. I managed to have a normal gentle brake stop and an emergency stop which stops the motor in about 1-2 revolutions from even 120Hz, less than a revolution from 50Hz. But it makes my 1/2ton lathe just about jump off the floor.... not something to do while thread cutting, only when you are already bleeding....

[shipto]

Thanks JHovel and yes I do have soft stop start enabled although I am going to lower the timer.
I have been reading through the manual for my inverter and came across a interesting operation mode option see pic, I currently have it wired in the first mode but the second mode will be much more useful, my reasoning being:
The speed control has limited use on the lathe as it has gears so a simple stop/start will do for that while the mill being direct drive needs the speed controller. So I can set up the forward/reverse switch close to the inverter and then put a simple start/stop on the lathe and a start/stop along with the speed control on the mill. This will also allow me to put a emergency stop in line on each machine.
I hope this make sense because it does to me.

[djc]

...So I can set up the forward/reverse switch close to the inverter and then put a simple start/stop on the lathe...

That bit does not make sense to me. If you are screwcutting and want to reverse the lathe, you have to walk over to the VFD every time you want to change direction.

[shipto]

I will be screwcutting left handed threads with a diehead. I can single point (imperial) without changing lathe direction.

[philf]

I will be screwcutting left handed threads with a diehead. I can single point (imperial) without changing lathe direction.

What about tapping?
I use the forward/stop/reverse switch every time I tap a hole in the lathe.

[Sea.dog]

Why the "Stop?"

The logic in a VFD uses the ramp parameters to slow the drive to zero then ramps it up in reverse. My pendant has no stop position between forwards and reverse.

[shipto]

I will be screwcutting left handed threads with a diehead. I can single point (imperial) without changing lathe direction.

What about tapping?
I use the forward/stop/reverse switch every time I tap a hole in the lathe.

Yes it would be useful for that now you mention it but as its now just a simple spst switch it would be no bother to put a second one on the lathe because as Sea.dog says the vfd ramps down the speed before changing directions. I have been thinking only in relation to the problem I have right now (a lathe needing to run in reverse for LH threading with a diehead) and had not considered anything else.

[philf]

Why the "Stop?"

The logic in a VFD uses the ramp parameters to slow the drive to zero then ramps it up in reverse. My pendant has no stop position between forwards and reverse.

It just happens that my fwd/rev switch has 3 positions and I find it useful if tapping a lot of parts to be able to just use the one switch for fwd/stop/reverse etc. I only have to press the start button once however many parts I'm tapping. Similarly if screwcutting an odd pitch where I can't disengage the half nut I can stop, withdraw the tool, and reverse all using the same switch. (The stop on this switch isn't the same as my my main stop switch - in the centre-off position it just doesn't tell the vfd which direction to run in.)

https://drive.google.com/file/d/1-liJppkibXJIGkOcGfOb3iw14_7U-rOG/view?usp=sharing