1 micromaster for 2 motors running alternately

Kataeb

Member
Join Date
Jan 2007
Location
www.livelovelebanon.com
Posts
628
Hy,

We are using the below mentioned Siemens motor, micromaster drive, and the following accessories in order to run an unwind:

Filter emc filter class B, 1.1 to 2.2kw, 6SE6400-2FL02-6BB0

Motor 1.1kw, 1415rpm, 7.4Nm, 2.55A, imb5, +kty, 1LA7090-4AA11-ZA23

Resistor braking resistor, 1.1 to 2.2 kw, 6SE6400-4BC11-2BA0

Inverter micromaster 440, 1.1 kw, 220 vac, 6SE6440-2UC21-1BA1

Profibus module for micromaster 440, 6SE6400-1PB00-0AA0

Power cable 4x1.5 mm2, 15.2 A, + total shield, 6FX8008-1BB11-3AA0



In fact we have 2 identical unwinds driven by 2 motors “1LA7090-4AA11-ZA23”.

When one of them is running the other motor is at standstill, each 30 minutes the running unwind will stop and in 200 milliseconds, the other unwind starts running.

So at a defined time only one motor is running, in 200 ms we will stop the first and switch to the other.

The question is: is it possible to run these 2 motors with one drive only and use two contactors (or 3 phase solid state relays) to switch from one motor to the other, instead of using 2 drives?

Thanks
 
You could but I am not sure why you would. There should not be any cost savings involved and if the drive did fail then the unwind would be down; while with separte drives at least one roll could always be available.
 
At 1.1kw, the drives are ridiculously cheap! Probably less money for the second drive than for the contacts and associated controls
 
I made a quick cost comparison:



The drive with its accessories (fuses, choke, resistor, profibus) will cost around 600 euros = 900 $. we have 4 unwinds which will make a total of 3600 $.



The solid state contactor will cost 128 $. we need 8 pieces, the total is 1024 $.



The saving is 2576 $ on one project. we make at least two projects each year.



Note that there will be reduction in software engineering, hardware assembly and cabinets space saving.



But I am concerned about the hardware safety in case of unvoluntary switching between the 2 motors.
 
If you really want to go this way then i would use 2 mechanical contactors both electrically and mechanically interlocked so you can only have one on at a time.

I dont know about the siemens drive but if i were doing it with an SSD drive 890 or 690+ then you could write a drive config to perform the changeover no problem depending on which motor is called for and have aux contacts from each contactor going to digital inputs on the drive to further interlock the two motors using the drives software.
 
Kataeb said:
I made a quick cost comparison:



The drive with its accessories (fuses, choke, resistor, profibus) will cost around 600 euros = 900 $. we have 4 unwinds which will make a total of 3600 $.



The solid state contactor will cost 128 $. we need 8 pieces, the total is 1024 $.



The saving is 2576 $ on one project. we make at least two projects each year.



Note that there will be reduction in software engineering, hardware assembly and cabinets space saving.



But I am concerned about the hardware safety in case of unvoluntary switching between the 2 motors.

That is BS, if cost that much then look into other suppliers.

For US people we are talking less than 2HP.

I can get a DRIVE for 2HP or so around $200.

Go whatever route you must.
 

Similar Topics

Hello Everybody, Recently we changed the gearbox which has different ratio than the original one on a motor which is controlled by Micromaster...
Replies
3
Views
1,864
Hello Experts I have to to make a backup of Siemens micromaster mm 440 with RS 485 to terminal 29&30. I use starter or drive monitor Do i need...
Replies
1
Views
1,193
:utoh: Hello, today tryed houres to connecting the micromaster 420 of my kaeser compressor to my laptop with the connection kit (MM4...
Replies
1
Views
1,677
My tutor asked me for this small project: using S7-200 control MM440 with PROFIBUS. Because S7-200 with PROFIBUS module EM277 can only be PROFIBUS...
Replies
4
Views
2,925
fault A0501 (i.e current limit ) displaying whwn i replace siemens 420 drive with mm440. all parameters are crosschecked. please help to...
Replies
4
Views
1,518
Back
Top Bottom