Thread: Wiring VFD to Arboga mill?

Looks like there are a lot of talented members out there, especially wiring diagrams.

I've got my Arboga mill, and a 240V 1-phase to 415V 3-phase VFD. The line in to the mill enters via a junction box, thermal overload, 2-speed switch then motor. The 2-speed switch I can probably ignor, or should I say, set to one speed or the other.

Attached is the wiring diagram that came with the VFD. What else am I going to need, eg, E-switch?

If someone could draft up a schematic diagram, I would appreciate it.

Reckon it would be advisable to mount the VFD in a case, to keep out swarf. Thinking maybe an old computer case might suffice.

Ken

Hi Ken
I had been thinking about pm you for an update.
If you fit a E/stop button/pedal(which I think you should), I don't think you should use the e/stop circuit on that VSD. Switch/break the 12V(green) wire instead. The E/stop circuit on these VSD relies on making a circuit, not breaking one. So you'll only know its not working right when you hit the button and the mill doesn't stop.
I don't think is breaking the 12V circuit and making the e/stop circuit will work either, even if it worked, the VSD would restart when the E/Stop button was reset if you forgot to switch it off manually.

The manual would say get rid of the 2 speed switch and the overload.
Stuart

Hi Stu.

Thanks for your advice. Sounds as though a hold in contactor should be inserted in the 240V lead. Pressing the E-switch would drop the contactor out, requiring a reset button to re-engage.

Does this sound ok? As I have mentioned many times before, I know very little about electrics.

I'll leave the 2-speed switch in circuit, but just won't use it. I realise that switching while the motor is running, spells sudden death for the VFD. I'll just take the knob off.

Drives Direct tell me it's ok to change speeds after the VFD is switched off via the pod, and the motor has stopped rotating.

Ken

This looks similar to the WEG CFW08 Variable Speed drive I got one for a 3HP motor for a big wood lathe.

I mounted mine in a case on the wall with the wires out the bottom.

The case will need ventilation so I positioned mine so it can run with the door open.

I'm not at home at present, when I get home, I'll get you some pictures.

I can't comment on the existing 2 speed switch without looking at it.

It looks like the SP terminal can be programmed as an emergency stop button but it doesn't come that way from the factory & I can't find much info on how to change it but if the value of Function 19 is changed from 2 to 3 that will make it an emergency stop button.
It looks like you would have it powered on with the remote pad set to OFF.
You may have press the run/stop button to make sure it isn't running.
Press the DSP/FUN button.
Press the up or down arrow til it shows F19.
Press the Data/ENT button.
The display should say 002.
Press the up or down arrow to change it to 003.
Press the Data/ENT button again to save it.
The display should change back to F19 afte a slight pause.
Press the DSP/FUN button again.

Now if the SP terminal is connected to the 12V terminal next to it via an emergency switch, it will cause the motor to stop when the switch is closed & allow it to run when the switch is open.

If you don't dare try changing the program then you could wire your emergency switch in the series with the 12V line on the remote control pad so that it is normally closed when the switch/button is out & opens when you hit the big red stop button.
That way the control box would still be powered up & would cause the motor to ramp down to a stopped state.
When you reset the stop button, the motor would start again straight away.

If you put it in the 240V line, then when you hit it, the power to the controller would go off & the motor would free wheel to a halt.
When you reset the stop button, the motor would restart after the controller had gone through its power up routine so there would be some delay.


Hope that helps.

Stu beat me & has a valid point.

Originally Posted by neksmerj

Thanks for your advice. Sounds as though a hold in contactor should be inserted in the 240V lead. Pressing the E-switch would drop the contactor out, requiring a reset button to re-engage.

You shouldn't turn the VSD off like that. I guess if you really didnt trust the VSD to turn off once you switched the 12V line off. I just cut the 12V on my set up.

Originally Posted by neksmerj

I'll leave the 2-speed switch in circuit, but just won't use it. I realise that switching while the motor is running, spells sudden death for the VFD. I'll just take the knob off.

Not sure it would kill it..... but it certainly wont do it any good.

Originally Posted by neksmerj

Drives Direct tell me it's ok to change speeds after the VFD is switched off via the pod, and the motor has stopped rotating.

Yes that would be fine.


Stuart

Originally Posted by Cliff Rogers

Stu beat me & has a valid point.

Well thats a first!

Stu,

You reckon "get rid of the two speed switch and thermal overload".

What's the danger of just leaving them as is? The thermal overload is obviously there for a reason.

It has been mentioned that the 12V lead be broken to stop the VFD. Buggered if I can find anything about this lead in the manual. What does the 12V lead do?

Ken

Hi Ken
Personally I'd keep the switch, but I would fit an interlock so it cant be switched with the VSD on(by on I mean the output of the VSD is on. Its fine to switch it is the VSD is "on at the wall" but off on the VSD. As Drives Direct has said). You also need the interlock set up in such a way that you cant turn the VSD on with the switch on the mill off. Either that or bolt a plate over the switch so it cant be switched.

The thermal overload is more of a worry. If it opens because the motor is to hot, to the VSD it's the same as using the switch on the mill to turn it off. So you might save your motor but wreak the VSD. Hopefully someone with more knowledge in this area can comment.

If you look at pages 15 and 17 of the manual(unless they have a new manual).
You see that terminal 5(12V) is the 12V for terminals 3,4,6,7(FWd,REv,SP1,RST).
At present I don't think you will be using SP1 or RST so lets forget about them.
The remote pod you have switches "terminal 5(12V) green wire" between either
FWd orange wire terminal 3
OFF
REv yellow wire terminal 4

I now see a problem. With the switch you have you can't just add another switch for E/stop, as when you reset the E/stop the mill will reset unless you have turned the switch on the pod off.

As I see it this leaves you with three choices
1. Wire it up as is with no E/stop
2. Wire it up and use the E/stop circuit of the VSD(my opinion of this is in another post.
3. Add an extra level of control (not sure what, I'll have a think)

Stuart

Hi Ken,
Some suggestions for you;
Emergency Stop. I would use a contactor on the 240V input side of the Drive that would drop out the latching side of the contactor. I would not trust the input command to VSD as it could fail, in industry it is the common practice to issolate the VSD in this manner in the case of an Emergency Stop.
Motor Two Speed Switch. If the VSD has an output that signals that the VSD is in a rest state use this to activate a contactor that would allow you if wanted to change the speed wiring to Motor.
Speed Pot. Wire this up as per VSD Manual.
Forward/Reverse. Wire this up as per VSD Manual.
Overload. The VSD should has an inbuilt Overload as an additional one would not be necessary.
Cooling for VSD. VSD's like a lot of cooling as allow at least 100mm arround all sides of the VSD.

Regards,
Keith.

Good luck Ken.

Originally Posted by Keith_W

Emergency Stop. I would use a contactor on the 240V input side of the Drive that would drop out the latching side of the contactor. I would not trust the input command to VSD as it could fail, in industry it is the common practice to issolate the VSD in this manner in the case of an Emergency Stop.

You could do it this way but as the VSD manual warns against doing this, I a couple of issues with it.
"Do not attempt to install or remove input or output connectors of inverter when the

power supply is turned on. Otherwise, the inverter may be damaged due to the surge

peak caused by the insertion or removal of power."

1. IF use did use this as E/stop you wouldn't be using it all the time. The problem with this is that when the time comes to use it you will most likely reach for the control you always use, not the E/stop which you haven't used for 18 months.
2. If you don't use it all the time it you don't know if it is going to working when you need it to.

If you use the VSD, you can use it all the time and if it fails you will know the first time you try and turn it off. With any luck at all that wont be the time you need it to work.

I've just come across this in the manual. (page 5)

The operation of the stop switch is different than that of the emergency stop switch. The stop switch has to be activated to be effective. Emergency stop has to be de-activated to become effective.

Which contradicts this. (page 39)
"When the external emergency stop signal is activated, the inverter proceeds to decelerate and stop"

This is a later version of the manual than I have, I'll check my version and test which is correct later today.

Stuart

Hi Stuart, Ken

On both the mill and lathe, I have the e-stop circuit dropping a latching contactor upstream of the vfd. So that e-stop kills the 240v power.

For normal start stop operation I use the digital inputs to the drive.

As far as thermal protection on the motor, (depending on the vfd features), the vfd will give you much better protection than a thermal overload. You could leave it in and I daresay it would never trip, but if it did trip while the machine was running, that should cause a fault trip on the drive.. probably dc bus overvoltage? I doubt it would damage the drive. But I wouldn't do it all the time..

Regards
Ray

Struth, are these things so delicate?

If it's suggested that there be no switching in the 240V lead, ie, an E-switch, how on earth do you turn the VFD on and off. I was just going to switch the VFD via the power point.

Ken

Ken
The warning about switching off the 240V only applies with the VSD is ON (i.e.running the motor).
Stuart

p.s. I like Keiths/RayGs idea of switching off the input, but I dislike the idea of two stop switches. Sometimes one must make choices in this world lol

Removing the power from the motor or the controller is NOT going to give you an emergency stop.... it will stop, eventually.

If you let the controller perform the ramp down, the motor will stop a whole lot faster then if you simply remove power.