Thread: VFD Circuit Diagram Question

This is Joe's VFD Circuit Diagram. (I think) I have deleted the jog sections as I do not need them for the lathe.

Joes VFD Circuit Diagram Revised.jpg

It appears to me that the EStop and the Stop do exactly the same thing. I was under the impression that they could handle different functions.

I wonder if the Stop switch should be moved to the D3 line. Any comments?

One comment I want to make is that D3 is actually the reset (RST) terminal in my case. This confused me as all other terminals are listed as they exist on the VFD. Maybe my VFD is different to others. I was going to ask about this, but reading the manual regarding the PD046 command cleared it up. It did take some time to get there tho.

Dean

Hi Dean,
If you use a latching e-stop it stops the VFD from being able to start at all. If you keep reading Joe's thread i describe how i set up my VFD, which is different again.

Ew

Hi Dean

The function of terminals D1-D6 are set by parameters PD044-PD049.
If PD046=04 then its stop.
If PD046=13 then its reset.
So basically forget the letter codes*, any terminal can be set to control any function.

The parameter PD0XX=13(e/stop) isnt used because its a NO circuit.. which doesnt make a lot of sense to me.

Stuart

*Well ok you have to use the letter code it work out which terminal is which..... but in my manual the last two are in the wrong order anyway.

I worked out that as momentary switches are used, my suggestion with the stop switch is no good.

Hi Dean,
If you use a latching e-stop it stops the VFD from being able to start at all. If you keep reading Joe's thread i describe how i set up my VFD, which is different again.

Ew

I know about the latching EStop, which is what I have. I could not find Joe's thread this morning, as I could not get to my normal computer due to SWMBO being still asleep. I was using my PC in the study which I am getting updated to work again after not being used for nearly a year. For some reason when I did a search for the thread I kept getting zero results. I cannot believe that for "vfd" or "vsd", so there is a problem somewhere.

I now have access to my other computer so I can look it up later. I had to scan a printed copy of the circuit diagram to post it.

Hi Dean

The function of terminals D1-D6 are set by parameters PD044-PD049.
If PD046=04 then its stop.
If PD046=13 then its reset.
So basically forget the letter codes*, any terminal can be set to control any function.

The parameter PD0XX=13(e/stop) isnt used because its a NO circuit.. which doesnt make a lot of sense to me.

Stuart

*Well ok you have to use the letter code it work out which terminal is which..... but in my manual the last two are in the wrong order anyway.

I know that too Ray. I was only concerned with which terminal on the VFD to connect the stop wire to. Doesn't really matter but I am trying to follow the KISS principal for now so I don't trip myself up and get into even more problems.

Re the EStop, I have a number of safety cutout switches on the lathe, some of which I will ignore and some I will use. The brake pedal is one example. These all need to be connected in series of course. I want to know where to connect them.

I recall a discussion where it was mentioned that the stop button worked via the VFD and the ramp down setting, but the EStop just shuts off the VFD which causes a slower speed reduction. ie No braking/ramp down.

I cannot disconnect the mains power via a control switch with my setup as I am using a 55A manual switch for power isolation.

The lathe is now wired up except for the EStop, the coolant pump which I don't have yet and the indicator lights which I also don't have yet. I will give it a run later today if all goes well. I have some other stuff to do first.

Dean

Originally Posted by Oldneweng

Re the EStop, I have a number of safety cutout switches on the lathe, some of which I will ignore and some I will use. The brake pedal is one example. These all need to be connected in series of course. I want to know where to connect them.

Same thread of Joe's Dean. On my phone so sorry i can't add a link. Best way to find it is to go to Joe's profile page and there is link on the left for "find latest started threads" or something.

Ew

I must have needed coffee Dean

http://www.woodworkforums.com/showthread.php?t=183843

You're going to have your brake pedal operate a latching e/stop?

Stuart

You will need the foot brak to tell the vfd to do a coasting stop not ramp down. Otherwise the brake will be fighting the ramp down. Honestly I don't think you'll need the ramp down anyway. Once you get the taste for the foot brake it is all you will use.

Ew

Dean,

you have to make a choice, how you want YOUR emergency stop to work. Every application is different.

I like to have my lathe e stop to halt the spindle "as fast as possible, NOW!". And that implies to use dynamic braking and keep the VFD powered up. But my two lathes are far smaller than yours, and do not have a brake pedal. My two lathes are fitted with mechanically settable stop switches that detect the apron approaching the headstock. In some cases I like to set these as emergency stops to avoid a collision for example when threading to a shoulder. It goes without question, that such apron stop has to work very fast to be any useful, it must use dynamic braking.

But there can be very good reasons, for an emergency stop to cut the power to the VFD. Every application is different. Maybe the following discussion gives you some food for thought:
http://www.plctalk.net/qanda/showthread.php?t=749
and
http://www.control.com/thread/998585364

Remember, every application is different. Do your own safety assessment, for your particular situation. Then choose how you want your estop to work. Your time spent thinking about it now, is well invested. The day you will have to press the estop, you will remember exactly what it does and in which sequence, you will remember what to expect and what not.

Thanks for the link Stuart. I am still on my PC because it is already up and I am just ducking in and out while I do other stuff.

The only latching stop is the one on the control panel as shown in my New Lathe thread. The others are as the lathe came, and only momentary switches. I still need to work out which to keep.

You will need the foot brak to tell the vfd to do a coasting stop not ramp down. Otherwise the brake will be fighting the ramp down. Honestly I don't think you'll need the ramp down anyway. Once you get the taste for the foot brake it is all you will use.

Ew

I am sure you are right about that, but what about the interlock switches? Coasting stop as well?

cba. Some good ideas. I will have a look at those links when I get time. Discussions like this help me to make decisions about what will suit me.

I will try connecting all required stop switches in one series circuit.

SWMBO got a tiger snake in the carport last night. She was warned, yet again by our golden border collie. Very unusual to have them out at this time of year around here. It was a warm day and we do have a lot of mice around.

Dean

Originally Posted by Oldneweng

SWMBO got a tiger snake in the carport last night. She was warned, yet again by our golden border collie. Very unusual to have them out at this time of year around here. It was a warm day and we do have a lot of mice around.

Dean

The dog is good at warning. But we are more worried at saving the dog from getting bitten. The cats are much faster, they can play with the snake. Trouble is they then want to bring the snake inside to show how good they are.... We keep cats around the stables to control mice. Because the more mice you have, the more snakes will come to you, since snakes eat mice.

Originally Posted by cba_melbourne

The dog is good at warning. But we are more worried at saving the dog from getting bitten. The cats are much faster, they can play with the snake. Trouble is they then want to bring the snake inside to show how good they are.... We keep cats around the stables to control mice. Because the more mice you have, the more snakes will come to you, since snakes eat mice.

This dog is good. This is why we are so happy with her behavior in this instance as she is a bit of a rag in most ways. She had a difficult upbringing and we are her third lot of owners. She wont be leaving here, even tho she only came here for 3 weeks break from her barking, for our son and daughter in law. She has learnt a lot.

When it comes to snakes she does not approach them, but stands back and watches while she gives her special "This is Serious" bark. We had a dog who hated snakes with a passion. We both saw her half in a huge Canna Lily plant jumping and shaking. She finally backed out with a large tiger snake held by its middle. We nearly fainted. We now try to discourage the dogs from going near them.

Back on topic.

Ueee wrote

Hi joe,
I'm just looking at it now. With my estop latched I get the panel flashing from A.ES to F00.00.
I can find my huanyang book again, but my estop is NO and when latched connects DCM to SPM. Not sure which pd's are set to what to make it work. Like I say I can't find my book, but if you want to know any particular ones just ask.

Ew

Joe replied

That would be PD048 set to 13..... interesting that it is a NO, since the 04 option is for a NC switch.... MMMMM
I really wonder if you can set different values for deceleration for an E-Stop? Can't find anything about it yet.
Anyone else?

On my VFD, SPM is set with Pd049. EStop is 13.

Ueee, I would appreciate a diagram of some sort so I am sure how it is done.

Thanks for the assistance Guys.

For the latest update on my lathe, refer to the New Lathe Thread.

cba. I have read the threads from your links. Certainly some helpful information there. One issue is that at this point in time, all stops, EStop or otherwise on my lathe are activated by an electronic circuit. There is no physical disconnect. This would require a contactor based mains power supply switch. I can do this but it would require a power source for the latching circuit. The contactors in the lathe require 110v. There is a transformer that has a 380v rated input and 110v output. If I used a 240v input this would equate to about 70v output. I would have to see if this would be sufficient to operate the contactor.

I am musing over having a system that applies automatic braking via the brake pedal mechanism. Hit the EStop, it releases and applies maximum effective braking. If I am wrapped up in the work, I don't want to have keep applying pressure to the brake pedal. This brake pedal is full length of the gap between headstock and tailstock base. The lathe was sold for little more than scrap value because the feed screw did not have a cover. I think the EStop issue is far more important, but I am not complaining.

There are interlock switches on the gear cover, the electrical box and the brake pedal. I cannot see any reason to change these.

I should point out that my experience with Safety lockouts, EStops etc is fairly comprehensive in relation to operation. At work every attempt is made to fully comply with regulations and any suggestions that indicate a further risk. We have stops everywhere. From everything I have read they seem to be fully compliant and then some. My mains power isolation switch for the lathe is lockable. For safety reasons, at times that might be desirable, but I doubt it at this stage.

Dean

Dean I found using a foot brake became second nature very quickly. Granted I do use the machine nearly every day, but I think you will find the same, the ability to stop the lathe without looking for the switch or moving either hand is great. So great I go looking for a foot brake on the mill......

I'll post some more details on the e stop when I am not on my phone.

Ew

Originally Posted by Ueee

Dean I found using a foot brake became second nature very quickly. Granted I do use the machine nearly every day, but I think you will find the same, the ability to stop the lathe without looking for the switch or moving either hand is great. So great I go looking for a foot brake on the mill......

I'll post some more details on the e stop when I am not on my phone.

Ew

Thanks Ueee. The Nuttall had a clutch lever and a big round stop button down near the floor level. Beacause the on/off switches were low down so I had to bend slightly to reach, I got used to flicking the stop switch with my left foot. I have no doubts I will get used to the brake. I do need to put it back together tho. I have not done so since I had the motor out. I need to adjust the motor position slightly to line it up. I will replace the brake bits after that.

Dean

Dean, this is your personal lathe and workshop is it? You have no employees using it, no plans to put on employess in future? You have full access control to your workshop, no kids to play around it? Then I would think you can do as you like. As long as you keep the electricals safe from starting a house fire. You can choose for yourself what degree of safety interlocking you want to put up with.

In this situation, I personally would consider to remove interlock switches on gear covers and electrical box. And certainly that most annoying of all safety switches on the splash guard - there are lots of routine tasks that are not compatible with it.
I would feel perfectly safe regarding the brake pedal as my only emergency stop (with a safety switch on the pedal of course, to prevemt the motor fighting with the brake). For me, no need for additional e-stops. I am old enough to look after myself. What I would never do without, is a plug that I can pull out of the wall socket, to positively and unmistakeably visibly from far away cut all power to the machine. Before and whilst doing any work on the electricals, I want to see that plug on the floor.

This whole argument changes completely, as soon as you share your workshop with someone else.