You are not registered yet. Please click here to register!


 
 
plc storereviewsdownloads
This board is for PLC Related Q&A ONLY. Please DON'T use it for advertising, etc.
 
Try our online PLC Simulator- FREE.  Click here now to try it.

---------->>>>>Get FREE PLC Programming Tips

New Here? Please read this important info!!!


Go Back   PLCS.net - Interactive Q & A > PLCS.net - Interactive Q & A > LIVE PLC Questions And Answers

PLC training tools sale

Reply
 
Thread Tools Display Modes
Old May 16th, 2003, 03:48 AM   #1
rajendrad
Member
India

rajendrad is offline
 
Join Date: May 2003
Location: Pune, India
Posts: 19
Abb Ac Drive

Hi Everybody,

I know this question is not related with PLC Automation but I can see peoples having in depth knowledge in other fields too and need your help to solve the problem.

We are facing problem on cooling bed inlet roller table drive. The drive has failed four times on Short circuit fault. However we did not found any problem on field side. The problem is Ė
Original 210 A drive (ABB make, ACS601-0210-3) was running since commissioning. This drive was driving 2.2 KW, 48 Nos (Total KW-105.6, Total Load Ė 221.3 A) of cooling bed inlet roller table motors. This drive was failed on Short circuit fault. The same has been send to ABB for repair. ABB service personnel informed that the problem was with card and they did replaced the same. Meanwhile these motors were run with other 120A drive. (Some of the motors kept off to match load with this drive). After receipt of Original drive (210A), the same has been put into service. The drive ran for five days and again this drive was failed on the same fault. Field side cables, motors were checked and nothing found wrong. After checking the drive, it has been found that IGBT of the same has been failed. Again all these motors were connected to 120A drive. This 120A drive was ran for around six months without any problem. Suddenly again this drive was tripped on short circuit fault. After checking they did found that the cable from drive to motor distributor board was faulty. They replaced the cable with new one. This time drive didnít failed. After this drive ran for a month and failed on short circuit fault. After this detail checkup done on field side but didnít found anything wrong. Now the motor load is distributed into different drives to run the system.
Presently these motors are running with other smaller capacity drives. After receipt of original 210A drive from ABB, system needs to be normalized.

We tried every possibility but....Need your help about how and what we should check to get this problem solved.

Thanks in Advance
  Reply With Quote
Old May 16th, 2003, 07:29 AM   #2
shahn4
Member
United States

shahn4 is offline
 
Join Date: Feb 2003
Location: Georgia
Posts: 104
Are you starting all motors at the same time? If so, the starting inrush current may be too much for the drive to breakdown. Also, It is not good practice to have 48-samll motors on a one drive.
You may want to put few motors on a second drive.
Check drive accel rate, overcurrent setting, overcurrent time, motor's inrush, etc.
  Reply With Quote
Old May 16th, 2003, 07:47 AM   #3
DickDV
Member
United States

DickDV is offline
 
Join Date: May 2002
Location: Kalamazoo MI
Posts: 2,310
rajendrab, I have a lot of application experience with ABB drives and will try to help you on this.

First, let me get a couple of things sorted out here. The drive model number doesn't seem to be correct. I suspect that it is an ACS607-0210-4. That last 4 might be a 3 for 380V operation. If that is correct, this drive is rated 210KVA, not 210Amp. My data shows 200amp continuous rating with 150% overload available for 1 minute in 10 minutes or 260amp continuous rating with 110% overload available for 1 minute in 10 minutes. You can expect this drive to trip on overcurrent or output shortcircuit instantaneously at about 295amps.

Second, do I understand correctly that you have 48 identical 2.2KW 380V motors all in parallel across the drive output. Is the 221.3amps you mention the total of all the motor nameplate amps at full load? If not, just give me the motor nameplate amps for an individual motor. If the motors are not all the same, please mention how they differ.

Third, This sounds like a steel processing line with each roller being driven by a single motor. Am I correct to assume that rollers have to start and stop occasionally with a load on the roller bed?

Please respond back with this info and I'll pick it up from there.
  Reply With Quote
Old May 16th, 2003, 08:37 AM   #4
rgua
Lifetime Supporting Member
Italy

rgua is offline
 
Join Date: Mar 2003
Posts: 139
Hi rajendrad

the inverter can feed a load connected to cables within a maximum length. The cables have a stray capacity which is an heavy load for the voltage impulses. The surge pulses may destroy IGBTs. If you connects 48 motors to an inverter you must check that the sum of the lengths of the cables is within the maximum.
  Reply With Quote
Old May 16th, 2003, 03:45 PM   #5
Alan Case
Lifetime Supporting Member
Australia

Alan Case is offline
 
Alan Case's Avatar
 
Join Date: Apr 2002
Location: Wagga Wagga
Posts: 1,263
I have seen 3 ABB drives destroy themselves in a big way when power to a switch board was turned on. Same configuration as above. A lot of small motors on long cable runs off 1 large VSD. As far as I understand (correct if I am wrong DickDV) but ABB sends out an interogation pulse (even when motors not called to run) to see what is at the end of its cables. This gets reflected back from the excess cable (not correct wording but you get my drift) and bang.
There are devices to correct this.
Regards Alan Case
  Reply With Quote
Old May 16th, 2003, 04:46 PM   #6
DickDV
Member
United States

DickDV is offline
 
Join Date: May 2002
Location: Kalamazoo MI
Posts: 2,310
Alan, powering up a drive is a stressful event and can be a point of failure if something is wrong. However, protecting against this is old science and most drives including ABB handle this without high failure rates.

As far as the motor leads are concerned, ABB drives are not deliberately putting any kind of signal out to the motor unless the drive is in RUN mode. In OFF or STOP mode, the motor leads should be inactive except for normal semiconductor leakages (which can kill, incidently!). Long motor leads should have no impact whatever on power up reliability.

As you can see from my above thread, I'm still looking for a few specifics from the original poster but, I'm pretty sure that this is a drive sizing problem and not a drive failure even tho there have been attempts to service it.

Starting a bunch of motors in parallel is like starting into a dead short and drive sizing has to be adjusted accordingly.

Let's see what data comes back, especially motor nameplate data.
  Reply With Quote
Old May 17th, 2003, 05:38 AM   #7
mdonner
Member
Israel

mdonner is offline
 
mdonner's Avatar
 
Join Date: Dec 2002
Location: Israel
Posts: 14
The cables length issue was addressed by rgua, and I want to add just this:
Manufacturers has a VSD output line reactor option, to be used if total cable length exceeds some value (usually 75' approx.).
Otherwise, IGBT failure may be expected (high voltage peeks due to standing waves phenomenon), which in turn may blow some components on a firing card and the firing control card.
This usually will not happen immediately, but after some peiod in service.
Offcourse there may also be a sizing problem (starting with load on cooling bed rollers) as stated by DickDV.
__________________
Moty
  Reply With Quote
Old May 19th, 2003, 08:01 PM   #8
DickDV
Member
United States

DickDV is offline
 
Join Date: May 2002
Location: Kalamazoo MI
Posts: 2,310
Well, it doesn't seem like I'm going to get any more data back so let's go with what we've got.

We've got a drive that trips instantly at about 295amps wired with 48 identical motors (I assume) with nameplate amps totaling 221.3amps.

In my view, the drive is sized WAY TOO SMALL for this application. In the first place, the impedance of 48 stationary motors in parallel is so low that the drive will almost surely conclude the motor leads are shorted and fault. This is not a drive defect but a desireable feature when the drive is used in any normal application. It can't be turned off in the software. Proper sizing for this application would be a drive with continuous output rating (with 110% overload for 1 minute in 10 minutes) of at least 150
% of the total load----in this case 221.3 x 1.5 = 332amps. In addition, I would expect that the rollers would be required to accelerate the steel slab rather quickly so there should be at least the same 150% overcurrent available for acceleration torque. In my experience, in steelmaking, 200% for 1 minute in 10 wouldn't be too much! This is rough service.

In an attempt to make the existing drive work as well as it can, I have the following suggestions. First, do not attempt to run in DTC or build any level of motor model. You must run in SCALAR (Para. 9904). Second, Para 2601 and 2602 must be set to NO and 2603 must be ZERO. In order, this shuts off FLUX OPTIMIZATION, FLUX BRAKING, and sets starting voltage as low as possible--no IR COMPENSATION. Third, I would set accel time as long as possible for the process and might even consider s curve rounding (Para 2206) of the accel ramp. Finally, I would experiment with current limit (Para 2003) gradually reducing it from the factory setting of 200% to a level that eliminates the overcurrent trip. Unfortunately, this will also tend to reduce maximum torque available in the motors for accel and starting. But that's the price for a drive sized too small.

Another consideration if the above is going to hurt the process too much would be to reduce the number of motors on the drive and add a smaller second drive set up to speed sync with the first drive. For example, you could run every third roll with the additional drive. This would possibly give you a level of redundancy too. Just remember to size the drives by the 150% rule I gave you above.

Another "trick" if you can tolerate some dead rolls would be to disconnect the gearboxes from every fourth or fifth roll and let the existing 210KVA drive run the remaining rolls. You would get much snappier operation (assuming the rolls don't slip too much) if the number of motors could be reduced.

One last thing regarding long lead lengths. A comment was made in an earlier post about long lead lengths and reflected waves damaging IGBT's. I have not seen this and also have never read anything along those lines. What is clear is that, on long lead lengths, due to the inductance of the leads, high frequency pulses from the drive encounter the motor and then reflect back up the leads. As they do this, they encounter more pulses coming from the drive and the voltage becomes additive. In fact, on 460V systems, it is not uncommon to observe pulses as high as 1600V at the motor. This causes severe stress on motor insulation and can destroy the motor windings if the motor is not rated for these pulse levels. Today, motors designed to meet IEEE MG1 Part 31 are generally ok with these pulses. It is important to note that these voltage levels do not appear at nearly the same magnitude at the drive output terminals. This is due to the inductance of the leads and the suppression diodes and other devices built into the outputs of most quality drives.

There is some debate about what constitutes "long" leads, but I consider applications under 250hp and leads under 250 feet not to be a problem. This further assumes carrier frequencies under 8000Hz. Above these numbers, or if you don't have an MG1 Part 31 motor, reflected wave suppression needs to be considered at shorter lengths.
  Reply With Quote
Old May 19th, 2003, 11:37 PM   #9
charlesfan
Member
China

charlesfan is offline
 
Join Date: Jan 2003
Posts: 17
I've heard same problems in China.
1st, I think for every motor, a seperate contactor is needed, for the INV protection.
2nd, are all motors working with same load?, I don't think so, the cunnrents must be unbalance. for multi motors control, I think the scalar control is the right choice.
in my view, choose a heavy load motor, add a tachometer (use closed loop ) let this one work like a master for spped ref. is better.
3rd, foolish way, disconnect the motors one by one, make sure which section is the "Killer"
  Reply With Quote
Old March 29th, 2006, 05:39 PM   #10
diggs
Member
Canada

diggs is offline
 
Join Date: Mar 2006
Location: alberta
Posts: 3
CJ1W-DRM21 used with RDNA-01 (ACS800)

Has anyone tried this combination? I can get the limited eds file to work, but as soon as I use the full version eds, for some reason I can't access all the parameters. In my Configurator it says "Attribute not supported" when I try and upload parameters from the RDNA-01. Does anyone have a CLUE? I have been trying everything. Could it be that there is so many parameters that my master just won't take it all? May stupid question, but I am totally up to any suggestions????
  Reply With Quote
Old March 29th, 2006, 06:06 PM   #11
Terry Woods
Member
United States

Terry Woods is offline
 
Join Date: Apr 2002
Posts: 3,170
Huh?
  Reply With Quote
Old March 30th, 2006, 10:22 AM   #12
Maj. Toxido
Member
Philippines

Maj. Toxido is offline
 
Join Date: Feb 2006
Location: Quezon City
Posts: 127
Smile

[Quote By: DickDV ]I would set accel time as long as possible for the process and might even consider s curve rounding (Para 2206) of the accel ramp. Finally, I would experiment with current limit (Para 2003) gradually reducing it from the factory setting of 200% to a level that eliminates the overcurrent trip. Unfortunately, this will also tend to reduce maximum torque available in the motors for accel and starting. But that's the price for a drive sized too small.



I agree with this!

I encounter a problem just like this, I set the acceleration ramp time and deceleration time higher,it works.

Last edited by Maj. Toxido; March 30th, 2006 at 10:26 AM.
  Reply With Quote
Old July 5th, 2006, 09:52 AM   #13
Vexare
Member
Canada

Vexare is offline
 
Join Date: May 2006
Location: Waterloo
Posts: 1
ACS 800 W/ RDNA-01 Parameter Trouble

Quote:
Originally Posted by diggs
Has anyone tried this combination? I can get the limited eds file to work, but as soon as I use the full version eds, for some reason I can't access all the parameters. In my Configurator it says "Attribute not supported" when I try and upload parameters from the RDNA-01. Does anyone have a CLUE? I have been trying everything. Could it be that there is so many parameters that my master just won't take it all? May stupid question, but I am totally up to any suggestions????
Hey

I've just run into the same problem with my ACS800's and RDNA-01 (Devicenet Communication Card) combination. I run into errors uploading and downloading the parameter configuration into RSNetworx for Devicenet. I started with Version 6, and upgraded to Version 7 after I talked with the ABB support guy. He was thinking that it was a problem with the AB software....I'm suspecting an issue with the EDS file that my vendor gave me. Hoping Digg's got his problem resolved so you can help me. Thanks
  Reply With Quote
Old November 5th, 2006, 10:18 AM   #14
swhite65
Member
United States

swhite65 is offline
 
Join Date: Nov 2006
Location: SC
Posts: 89
If you have listed the right fault ("short circuit problem") then this is not the same thing as other current faults. The setup data for group 99 mentioned above should be verified. Also, make sure the current parameter value is the sum of all nameplate currents. In my experience with these drives, this fault would pop up if there is an internal problem with the drive (board or IGBT problem), or a problem with the cabling. An overload would cause other faults to appear. This drive can be very sensitive to cabling issues, especially longish runs that have been there for a while and you don't really know what might be in the conduit, cable tray, etc. like moisture or other contaminants. Some of the items mentioned above might help but you might want to do some separate testing on the cables to verify their integrity.
  Reply With Quote
Reply
Jump to Live PLC Question and Answer Forum

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Topics
Thread Thread Starter Forum Replies Last Post
Device Net with AB 50/4 and ABB Drive 504bloke LIVE PLC Questions And Answers 37 March 30th, 2006 02:58 PM
Synchronous AC Drive bwheat LIVE PLC Questions And Answers 13 September 2nd, 2004 12:21 PM
Abb Acs 600 Ac Drive PLC BOY LIVE PLC Questions And Answers 2 July 18th, 2004 01:46 PM
ABB ACS 600 Drive unit chorn46562 LIVE PLC Questions And Answers 1 May 27th, 2004 10:27 AM
Abb Ac Drive Failure rajendrad LIVE PLC Questions And Answers 3 July 21st, 2003 06:00 AM


All times are GMT -5. The time now is 08:50 AM.


.