UKC

I've acquired a good old hunk-of-cast-iron lathe; 3 phase motor.

I've got a cheap VFD and reconfigured the motor to delta/low voltage.  Runs beautifully from the panel on the VFD.  I've also managed to get remote speed control with a potentiometer.

My challenge is now wiring the control switches.  Ideally I'd like to use the buttons on the lathe for start stop.  These are momentary NO and NC switches which used to work via a relay box.  I did think about just putting the whole lot, including relay, upsteam to control the 240V input, but apparently stopping the VFD by effectively cutting supply isn't good for them.  Also there are some safety microswitches that I will just keep in series with the off button.

The VFD seems to require continuous input so it runs while I hold in the ON button, but not when released (i.e. On is acting like Jog).

What am I missing?  The pamphlet that passes for a manual is in English that's been through Google translate or a human Chinese equivalent.

Parameters I can assign include (just the more hopeful ones):

1.  Wire control stop

2. Keying stop

3. keying operation

4. Stop keying (how is this different to 2?)

5. Wire forward operation - I have tried this and it runs while closed

6. wire reverse operation

7 Reservation

9. Wire reversing switch

10. keying forward switching

11 keying forward switching (again)

19 emergency stop

20 relay control

Is there a combo that keeps my kill switches?

I'm afraid I'm not sure from your description exactly what is going on.  But If I were doing it, I would try to get the VFD on all the time, and put all the lathe's original switchgear and relays downstream of the VFD and configured as they were originally. This will keep all the lathe's safety features, some of which (such as an NVR preventing surprise restarts after a mains power loss) may not be obvious. Assuming it is a decent lathe which has all the necessary safeties and meets the Machinery Directive of course. Also, if the lathe has mechanically variable speed, I would use that in preference to the VFD where possible, to keep the torque up and extend the motor life. Unless the lathe was designed to work with a VFD?

Beyond that, I think you might need to draw a diagram of how it was wired and how it is now wired. And if you're asking how to make the VFD come on and stay on, you might need to post a link to the manual. I also wasn't clear if the VFD and Lathe have separate on buttons, which one you were referring to when.

Only expensive VFD have truly safe run enable inputs, even ABB controllers of the lower series can lose memory and revert to a none-safe default where run enable is actually respected.

Personally, I would use a relay on your existing On Off to give you a latching run enable signal. You'll need a relay with two isolated switches so you can use one latch the delay and one to loop the run enable signal to the VFD. Use the off switch to break the latching.

Pull the relay power from the input to the VFD. Leave the safety switches also on the input side. If they kick in the VFD stops regardless and if it gets broken at least you're safe.

Then when you turn the isolator to your lathe to on the VFD powers up. The on starts it and the off stops it but the VFD stays powered.

What's the VFD make and model?

you should be able to configure for a number of different start/stop/run options.

The VFD might be better as a safety device, as it can actually brake the lathe, though you will need a big resistor to get rid of the energy, if the drive has provision.

It's a Chinese cheapy - AT1 2200 I think.

I've made some good trial and error progress and got the momentary buttons to do what they should.  I'm looking at the micro-switches today!

Is there any reason why you can't just use the VFD always on (or at least enabled/disabled once per session) in place of the usual 3-phase supply (albeit now variable frequency), keep the rest of the lathe's switch gear as was? Especially with the shonky instructions providing very little reassurance you're setting it up to fail safe I'd be very wary of it while changing belts/gears/work with the machine live, a broken wire or a processor restart and you're missing fingers or limbs in no time!

jk

Jow much did that cost you?

£50

Because he'd have to interrupt the output from the drive and that's not the best way to run them. It's a good way to f*ck them up, especially cheap ones.

Hi,

Looks reasonable, I've downloaded the manual, It's funny.

The numbers in your OP are the functions you assign to the inputs X1 to X6, when you make those the drive will do what it's told to depending on what settings you've used.

I'm assuming the numbers in the 4th column are the default settings, so input X1 is set to 13 and will run the drive at section (selection) speed 45Hz ( as set in P27) the next two inputs will select different speeds depending on P28 and P29 and relating those to Table 3. I hope you're following this, ha ha.

X4 makes it go forwards

X5 makes it go backward

It makes me wonder what would happen in you had both on

X6 is a mystery (wire reversing switch!!) though this might be to change the phase sequence, so forward is actaully forward ( but you'd normally just swap two phase out to the motor ).

P10 is where you want to control it from, either locally on the drive, external analog signal (potentiometer) or via comms.

It talks about SP1 as a Multifunction Input 1 (SP1) but I think it's really an output, looking at the terminal listing.

I would usually look at wiring a "Start" signal and a "Not Stop" but that would depend on how it works in practice, i.e. you have to remove the stop signal and make the start signal for the drive to run.

I have no idea what "Keying" is.

Sounds like fun, I'm really busy at the moment, but if you want you can let me know what you want to make it do and I'll try and help you out.

It looks like this is the same drive XSY-AT1 VFD, so Google that and there are some discussions and help regarding that drive which will probably help translate the instructions.

Before you commit stuff though you might want to look up a stop/start circuit, this will ensure the drive stops if the power drops out and wont start again without pressing the run button again. You don't want the thing to run by itself.