Two speed motor and VFD

[Hood]

I am thinking about fitting a VFD to my Arboga drill. It has a 2 speed motor so obviously I will need to choose one or the other to connect up the VFD.
The drill has a gear box so changing speeds is not a problem and really the only time I will increase/decrease the Hz of the VFD is when wanting to change to the equivalent of the low and high motor speeds I currently have.

I am thinking it would be better to wire for low motor speed and use the VFD to increase the Hz for the higher range if required. My thinking is I would have the most torque on lower speeds than if I did it the opposite way round. Would this be the best way?

 

[daleyd]

I “think” your correct in your thinking (I’d need to check as I can’t remember if it holds true for multi speed motors, though i think it does...) but really it’s up to you to decide what you want and if you need the extra torque.

As you overspeed the motor past it’s nominal frequency you’ll certainly get a reduction in torque, so what you gain at low speed you’ll lose at high speed.

Personally I’d be tempted to do it on high speed (most drives will have a torque boost facility which you can program to kick in at low speed) - if it doesn’t work out you can always change.

 

[Hood]

After sleeping on it I am wondering if I should do the opposite
Way I am now thinking is that as I will want double the speed that would mean I have to increase the Hz to 100 if wiring up the motor for low speed. As the motor is old and integrated into the drill body then I may be unduly stressing it and that is not something I want to do as a replacement will be hard to source.
If I use the high speed wiring then to get the half speed it would be a drop to only 25Hz and although the torque would be less due to the VFD slowing it down there should still be plenty due to the gearing.

I have several VFD's here and Old Siemens Micromaster, a newer Micromaster 420 and a couple of Lenze 8200's. The Lenze are definitely Vector drives and if I recall they will compensate for low speed torque.

 

[daleyd]

Micro master 420 will also torque compensate (in fact torque will actually remain fairly constant through the speed range, apart from the very bottom end - power will increase with speed ).

If you have the software and a serial adaptor (I seem to remember you need a 232 - 485 adaptor as well) it’s easy to play around with them, I can send you some stuff if you haven’t got it.

 

[Hood]

I think I have an adapter that mat be suitable, it is for my Chirons drive (Telemechanique/Schneider) but can't recall exactly how it connects, may be RJ45. I did have one of these https://www.ebay.co.uk/itm/KMTronic...f-RS485-BOX-/281257472778?hash=item417c40730a but gave it to a friend.

Just looked and the Micromaster 420 doesn't have a keypad but I have one for the Lenze so I could do things manually if I had to on it. The micromaster has buttons integrated so again it could be used manually but not sure if it compensates at low speed.

As you say setting up via a laptop is the easy/quick way so I will have a look around and see if the software is available.

 

[daleyd]

I can send it you if you can’t find it - I seem to remember it was a bit of a faff to find it on Siemens website amongst the paid for stuff (the micro master software is free).

My work laptop is having a new hard drive fitted but I think I have it on my home laptop.

 

[Hood]

I have just found this.

Not sure if it has the software on it or not but will go take a look.

 

[Hood]

It has Drivemonitor on it which I think may be what I am looking for but it took an age to install and even though I chose English for the install it is opening in German
Will have a mess around with it later and see if it is what I am looking for.

 

[daleyd]

Ha ha I barely understand English so it’d be no good for me!!

Starter was the software I had, should be in their website but I’m not keen on the navigation and finding stuff is a pain.

 

[Hood]

Well I went through the menus and found one that said Sprachen, I figured that was language so I tried and now I have it in English, or at least it seems to be although to be honest it seems to be double Dutch at the moment

 

[Hood]

.....Starter was the software I had, should be in their website but I’m not keen on the navigation and finding stuff is a pain.

Looks like that may be on the CD as well.

 

[daleyd]

Yeah that looks like the more comprehensive software that has starter included, though I’ve only ever used the basic package.

In my previous company we made a machine using Siemens Sinamics/Simotion drives which had an integrated plc - the license for the software alone (Siemens Scout) was about a grand!!

 

[Hood]

Tried to install the Starter Standalone and it threw an error saying it needed NT/W2000 or newer
So tried to install in compatibility mode and it seemed to work but on reboot it threw an error. I see there is an Update folder, will see what is in that.

 

[Hood]

Now downloading Starter from their site, found it easily enough via Google but the registration was a PITA, these Germans like to do things the hard way

 

[daleyd]

Yeah I found the link on my phone earlier - I really can’t remember why I struggled when I tried to find it on my laptop - maybe they knew I was downloading it onto a Schneider electric laptop ha ha

 

[Hood]

Ha ha well just installing the Lenze software, the bleeding Siemens one is still downloading.
Talking of Scneider, when I got the Telemechanique drives for my Chiron it looked like I was going to have to buy the software, RS was selling it for big ££££'s I then went to Schneiders site and lo and behold a free download

 

[daleyd]

Ha ha well just installing the Lenze software, the bleeding Siemens one is still downloading.
Talking of Scneider, when I got the Telemechanique drives for my Chiron it looked like I was going to have to buy the software, RS was selling it for big ££££'s I then went to Schneiders site and lo and behold a free download

Before I worked for schneider and before they changed their name we used to use a lot of telemcanique drives and soft starters (Now Schneider) and we always had to buy that software (plus the daft cable connection kits needed).

I was glad to see we changed philosophy, as the drives became too complex to commission and faultfind without the software, at least beyond the basics.

Lenze stuff is quite good too, gdc easy is their free offering and it does almost everything the full version does other than logging iirc. The lecom comms adaptors were horrendously expensive though, I wish I would have kept hold of mine when I left !

You really need the software with Lenze servo drives (9300 servo were the ones we used, as well as their 8200 vector drives), the amount of parameters are mind boggling.

 

[Hood]

Have a couple of these servo drives with motors.

Not used them yet so never had to mess around. They have the button panel so could I suspect be done via that but I can imagine it would be a real chore and I would soon be throwing things about

 

[daleyd]

They are the ones we used to use, ours were a bit bigger though, but the same drives.

You can do the basics with a keypad but anything more involved is a nightmare. The manual is hundreds of pages long!

Do you have the matched motors - ours used resolvers for rotor position info, I’m guessing you need either these or some kind of encoder to give feedback? You might be a able to use them as a normal vector drive without feedback but I’ve never tried.

 

[Hood]

Yes, have the associated servos, if I recall they have Sick Stegmann sine/cosine encoders on them.