Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: sommerjd on August 19, 2008, 12:30:56 PM

Title: AC vs DC Servo Motors
Post by: sommerjd on August 19, 2008, 12:30:56 PM
I just picked up some servo motors from an industrial excess site.  All the information I looked up stated they were AC servo motors or at least the controller was AC.  Is there a specific motor that is made for either AC or DC voltage?  Can they be used for either AC or DC depending on the controller used?  Each of the motors have 4 pin connections coming out of them, where all the schematics for the DC hookup show only two wires for the hookup.  Can someone enlighten me on servo motors and if I can used the ones I have for a DC application?

thanks.
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 19, 2008, 01:47:53 PM
Do you have any info such as name and model of these motors?
 AC servos and Brushless DC servos are basically the same thing, it is the drives that are different, then there are normal brush DC servos, they are completely different.
Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 19, 2008, 02:59:00 PM
I have three different brands.

Reliance electric Y-2012-1-H00AA
IDC Model B23-B-CO
Rexroth MSM030C-0300-NN-MO-CC0

They all have 4 pins coming from the motor.  The line diagram for the Gecko controller shows only 2 wires going to the motors.  If I were to use these motors, which of the 4 wires are wired to the Gecko controller?

thanks
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 19, 2008, 03:05:17 PM
I know for a fact the reliance are AC servos, I use bigger versions of these on the lathe, they are 2000 line encoders. Will have to search for the rest but am a bit busy at the moment.
Hood

Edit BTW Geckos wont drive them
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 19, 2008, 03:50:22 PM
Your IDC is also an AC servo and cant find anything specific about the Rexroth but I do have a manual for a slightly different model number and it to is an AC servo. None of these motors will work with the Geckos as they are for DC servos.
Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 19, 2008, 04:25:58 PM
Maybe I am stuck on using Geckos, but is there anything out there that will control these AC servos and use Mach3 to control it?  I am assuming there are AC controllers out there that use step and direction similar to the Geckos.  I think I am stuck on the Geckos because of the price and the amount of support out there for information.  I also have a Rexroth Ecodrive Cs, but I am not sure how to hook it up for step and direction.
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 19, 2008, 04:28:52 PM
Lots of drives will work with these motors, not sure on the Rexroth, they may have resolvers but possibly the Rexroth drives are fine withthat. I will have a search and see if I can find info on the drives you mention. Do you have a model number for them or is that it? If you have a link to any documentation that would be good as well.
Hood
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 19, 2008, 04:39:48 PM
OK found info on the Rexroth, need a drive number but it looks like your motors have encoders so that bodes well.
Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 19, 2008, 04:39:58 PM
I found this sight that has a ac servo driver similar to the gecko but for AC servo motors.  Is there an advantage or disadvantage using AC or DC?  Here is the site....

www.logosolinc.com/download/ls-182.pdf


Thx
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 19, 2008, 04:44:00 PM
AC are the best in my opinion. Before you go looking at other drives let me know what model Ecodrives you have, they may do and they will be as good as any drive you can get I would imagine.
Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 19, 2008, 04:52:04 PM
I have the one with the Profi Bus.  The only part number I see is Ecodrive Cs with EC M01 1-PB01-NN attached to the side.  Here is the web site....


www.boschrexroth.com/.../en/products/brc/ProductDocumentation/CurrentProducts/Drives/EcoCs/29575802.pdf

Thx
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 19, 2008, 05:58:45 PM
Will have a look and see what I can see, lots of these types of drives can take all sorts of Inputs but some may be specific, hopefully the manual will tell me.
Hood
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 19, 2008, 06:52:11 PM
Not finding much for the number you gave, your link returns an error as well. I have  found a manual that  deals with the ecodrives so will look through that. Its getting late here so it wont be tonight but  if I havent responded by this time tomorrow bump this thread by posting again and that will remind me ;)

Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 20, 2008, 09:33:01 AM
http://www.boschrexroth.com/country_units/america/united_states/en/products/brc/ProductDocumentation/CurrentProducts/Drives/EcoCs/Firmware/MGP01/MGP01_FV01.pdf

Copied the link correctly this time.  I have the one that is pictured in the middle of the front page.
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 20, 2008, 02:38:19 PM
From the looks of it your drives may not accept step and direction inputs, its hard to say however as these manuals dont really give much detail, they refer to parameters and I cant find these parameters. I think there must be other manuals so will see if I can find them.
Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 20, 2008, 03:24:07 PM
I also have the Allen Bradley Ultra3000 drive.  If it states that it has step/direction option, will this work with Mach3?  Also how does the voltage work with the AC servo drives.  Do I look at the max rated voltage on the motor and get a controller that is above that rating or below?

Thanks.
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 20, 2008, 04:04:02 PM
Now you are talking :)
 I use the Ultra 3000 drives, they are great :0
 Voltage determines the speed, current determines the torque. If its the normal DSD drives you have they are 120 to 240v input, if its the HV versions they are 240 to 480 input.
 Let me know the model you have and I can advise better. Would imagine your motor is 240V so thats what you want to put into the drive.
Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 20, 2008, 05:59:44 PM
The drive states the input voltage as 100-240 volts.  When connecting motors to this drive do I look at the specs of the motor rating and make sure the input voltage is higher?

Thanks
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 20, 2008, 06:26:20 PM
Yes basically, you can go lower if you wish but if your motors are 240v ones then you will only get half their rated speed if your input voltage to the drive is 120.
 You cant just stick any AC  motor on the AB drives, well you can but you may need to do some tricks, will cross that bridge if you need to ;)
Do you have enough AB drives and motors for what you need or are you planning on mixing and matching different motors to these drives?

Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 21, 2008, 03:33:05 PM
I am planning on sticking different motors that were listed at the first of this topic onto the AB drives.  I have a couple of the motors pinouts that I can work with in connecting the motors up to these drives.  I am just not familiar with what to hook up to and where with the AC servo motors.
Title: Re: AC vs DC Servo Motors
Post by: Trollyjack on August 21, 2008, 04:52:55 PM
Hi I'm new to all this just decided to build my own cnc
at the moment I have aquired 3 stepper motors
1 says its a dc stepper motor 2.8volt 2amp and its 2" square. 6wires
the other two are larger may be 4" square I have been informed that these are 2amp also, but there is no identifercation on these how do I find out weather they are dc or ac these are 4 wire
if I connet them up to my power supply and try to run them with it blow them or the power supply

Thanks
Kev
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 21, 2008, 05:36:11 PM
I am planning on sticking different motors that were listed at the first of this topic onto the AB drives.  I have a couple of the motors pinouts that I can work with in connecting the motors up to these drives.  I am just not familiar with what to hook up to and where with the AC servo motors.
By the first motors are you meaning the reliance motors? If so then that is a good choice as they are the same as the Allen Bradley Y series motors and should plug right into your drives :)
 First however you need to make sure your drives are big enough, the motors you listed (Reliance electric Y-2012-1-H00AA) will need a DSD-020 drive, if they came with the motors then the chances are they are correct but have a look and make sure.
 Do you have the UltraWare software? you need that to set up the drives.
If you have any questions or doubts about these drives and motors please let me know as I am very familiar with the Ultra 3000 drives, I have them on my lathe and the mill I am retrofiiting at the moment.

Hood

Oh and almost forgot the reliance motors you have listed are 115v motors so you only want to feed your drives with 115v. Are you in the USA? If so your mains will be 115v between live and neutral I think.
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 21, 2008, 05:39:39 PM
Hi I'm new to all this just decided to build my own cnc
at the moment I have aquired 3 stepper motors
1 says its a dc stepper motor 2.8volt 2amp and its 2" square. 6wires
the other two are larger may be 4" square I have been informed that these are 2amp also, but there is no identifercation on these how do I find out weather they are dc or ac these are 4 wire
if I connet them up to my power supply and try to run them with it blow them or the power supply

Thanks
Kev

Do not connect steppers or AC servos direct to a power supply.

If they are stepper motors then you need stepper drives for them. You will know whether they are steppers or not by whether they have some form of feedback, ie if they have an encoder or resolver on the end they are servos, if they dont then they are steppers. If you post a pic of them we should be able to tell.




Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 22, 2008, 01:15:53 PM
Is it just AB that is difficult to match the drives with a motor or is that a general rule with AC drives?  I know that AB is a very good product, but seem to only work with AB motors.  Is there a generic drive that would work with the different motors I have.  I just don't come across very many AB motors in surplus.  I don't have the Ultraware software to set up the motors.  Would I be better of selling the AB ultra 3000 drives on ebay and take the money to buy a generic AC drive?
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 22, 2008, 01:24:33 PM
Up to you if you want to sell them but I think you would be crazy. If you do decide to sell then I know a few people who may be interested depending on the models and the price you want.
 You can use ANY synchronous  ac servo motor on the AB drives as long as it has the right feedback/commutation and is within the drives specs for current and voltage. I bought a big motor that I knew was not suitable for the AB drives due to the resolver, I also bought a tiny motor that had a suitable encoder on it, I swapped the encoder onto the big motor and aligned  it and its perfect :)

Let me know exactly what model drives you have and what model motors and I will be able to tell you if its possible without adaption to use them.
Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 22, 2008, 05:18:19 PM
I guess you don't know what you got until its gone.  The motor part numbers are at the first of this topic.  The exact model number of the drives I will need to get next week when I pick up the drives.  I do know that the Reliance motors are 115 v and the Rexroths are 114 volts.  I can't find anything as far as voltage for the IDC motors.
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 22, 2008, 05:22:51 PM
Ok so how many drives do you have and do you just have one of each of the motors? The Reliance motors will plug straight into the AB drives, will have to check up on the other motors to see. Dont want to spend time trying to find info if you have enough reliance motors to do what you require, so let me know please.

Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 27, 2008, 12:30:29 PM
The Reliance motors I have 2.  I have 4 IDC motors.  I have 2 Rexroth motors.  The part number for the Ultra3000 drives are 2098-DSD-005 and I have 4 of these.  The version on the Ultra3000 drives a Firmware V1.32.
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 27, 2008, 02:14:19 PM
Afraid your Ultra drives are far to small for at least the reliance motors and I think also the other motors you have. The drives are 5 amp continuous and 10 Amp peak if I remember correctly. You will need a DSD-020 drive for the reliance motors.
Hood
Title: Re: AC vs DC Servo Motors
Post by: sommerjd on August 29, 2008, 05:08:39 PM
What do you look for on the motor specs to determine what drive to use?  When I look at the specs I get overwhelmed with the amount of information that is listed.  I am use to the stepper motors where most motors can be hooked up to my stepper controller.  Will the controller blow if I use a motor that is drawing too many amps above what the controller is rated for?  Can I still use the motors and just not max out the amps on too big of a load?  I am just interested in learning about servo motors now with the encoder feedback.  I do have a stepper motor system that is working good, but just want to expand my horizons.  Thanks for all your help on this subject.  I also just picked up another Rexroth Ecodrive CS drive that I think match right up to the rexroth motors I have.  I am just not sure if the controllers are step and direction driven.
Title: Re: AC vs DC Servo Motors
Post by: Hood on August 29, 2008, 08:22:54 PM
You need motors that fall within the current range of the drives and also the voltage range. If you have a drive that is 5 amp continuous and 10 peak and a motor that is 5 amp cont and 12 peak then that will be fine but having one that is 7amp cont would cause you problems. You would probably find that the drive would constantly trip on overcurrent, not likely to kill the drive but not likely that it will be much use with the constant tripping. It is obviously best to get motors and drives that are matched. Also even with a matched motor/drive if you are trying to drive an axis that is too heavy for them they will trip but that is just a similar situation to a small stepper trying to drive an axis that is too big.
 Another thing you will need to match up is the feedback, some drives can take resolver feedback, some require encoder feedback and some can take either, same with commutation, some use Hall, some use ABS etc etc.
 I think from the look I had at the Rexroth it depends on the model you have whether it will be any use, you need a drive that will accept Step/Dir signals, some manufaturers call this by different names such as Pulse/Direction, Pulse/Signal etc.
 With the Reliance motors you have you will need DSD-020 or the older DDM-020 or DDM-019. If the motors had been the 240V versions then the current would have been less and a DSD-010 (DDM-010 or DDM-009) would have been enough.

 Not sure what you are doing with the Reliance motors but I am on the lookout for an encoder for an 8 Pole motor of which the Y series motors you have are, so if you decide to get rid of the motors let me know as I may purchase the encoders from you.

Hood
Title: Re: AC vs DC Servo Motors
Post by: LantonioA on July 03, 2011, 10:12:15 PM
I just register on this Forum, and I think my answer is a little too late, but I'll try anyhow. The Reliance Electric motor's (Y-2012-1-H00AA) part number that you've mentioned is identical to the Allen Bradley's, I have a few Y-2012-2-H00AA which are 220V because of the number "2" on the middle two as follow:

Y        =   Series Designator
#### =   Frame Size  -  12 is the continuous stall torque in Inch/pounds
#     1 =    115V Drive input volts       2 = 230V Drive input voltage
H        =   Incremental encoder (2000 lines/revolution)
00       =    No brake         04  =  24V DC Brake
AA      =   Standard (or Metric)

Your drive won't work because the ####-###-005 are only 2.5 continuous amps. If your motor was a 220V a ####-###-009 would work, since is a 110V you will need at least ####-###-019 Drive.

Luiz