Problems with Blower.. Overflow or mechanical issues !!

Hi, I am a Graduate student and working with a Fluid Bed Dryer. My background is not in engineering, so I am facing a lot of troubles. I tried to learn by myself through different lecture videos without much success. Hope this forum would help me out.

Our blower in the FBD stops working frequently. Earlier we used to do "Clear Fault" using RSlogix500 software in which the ladder logic program was written by a professional. The reason was said that "While resting, there is a pile up / overflow of negative/above max value for the blower, which causes the fault". Fault clear used to work, although, when I used to open that ladder logic program and go online, it used to show "RUN" not "FAULTED".

From last couple of months, the "Fault Clear" is not solving the issue. The blower stops working, I do the same thing (Clear Fault using RSlogix 500) but nothing happens. And surprisingly after couple of days the blowers starts by itself !!

From my experience of 4 months, the blowers stops working in a certain scenario. We use automation system using Delta V and Micrologix 1100. When the set value in the specific tag for blower flap position resides at maximum or negative value, and we start the power up for Fluid Bed without changing the value, the blower stops working and never comes back.

Can anyone help me out please. I am just getting frustrated without appropriate knowledge and skill in this arena.


Thanks,

Anik

Software limits

With the limited information given it sounds to me like there should be some software limits programmed into the logic to prevent the overflow or the maxing out of blower limits. Without knowing what creates these numbers or how they are used its hard to say that is the correct solution. I would look into what cause the overflow and figure out a way to prevent them logically in the software.

Thank you very much for your reply. I am not a technical guy, but trying to describe as much details as possible.

We use synTQ, Delta V and Micrologix 1100. There is a "tag for Air flow in synTQ" system. When I set a value there, another "tag (for airflow) in micrologix" tries to get the same value. This tag represents the measured airflow in the Fluid Bed.

To adjust the same value, it changes the blower flap position from 0-100%. When the FBD is off, the default value of the "micrologix tag" becomes static. No matter what the value is in the synTQ tag, the system tries its maximum to get the same value in the micrologix tag and set the blower flap position in either "100" or "negative".

The blower is not working right now. Neither manually nor remotely. We have a ladder logic program, which used to solve the issue by clearing the fault. But this time its not helping.

I am really sorry for being ignorant in this issue.

Thanks

Post the .rss file, the ML1100's program file here. Zip it first.

Save the program while it is in it's faulted condition if possible, then post that file.

can you post the ladder logic?

Communication

As others have said, having the logic file would help us decipher what the issue could be. Sounds to me like there is a communication issue between the Delta V and the micrologix. There should have been code created to both alert and react to the situation.

I would guess that there is a separate issue with the blower motors though if they wont work in manual. This usually bypasses the logic inside the PLC. I would say you need to physically check the motor circuit.

Hi, I have attached the file here. When the blower used to stop working, we used to go online and "Clear Fault". This used to solve the issue. Although when I went online, the mode was saying "RUN" not "FAULTED". This was suggested my previous lab-mate.

I am only working with this for 3 months. Again sorry for my ignorance.


Thanks

Programs don't change. The blower doesn't work in manual? Describe Manual - at the VFD?
I suspect it was getting overloaded and faulted. Another idea is a loose wire.

Clues: 1) Program is in run - not faulted.
2) Blower started by itself after 2 days.

Program is fine. Fix the blower or VFD.

The only rungs I see a potential overflow problem are Lad 2 rungs 7 & 9. You may want to consider using a "Limit" instruction ahead of the "SCP" instructions. See sample below.

Hi, I have checked for the physical fault. There is a contactor K1 which is connected with the blower. If I press the contactor manually, the blower starts working. But it stops when I release the contactor. There is a pressure switch also, which seems fine. It seems to me that, the blower is fine as well as the contactor and pressure switch, however the contactor is not getting the signal.

There are two relays K10 and K11 for manual and automatic. Earlier it used indicate green and the VFD display used to show run mode. But now, even it turn it manual, the K10 relay indicates yellow and there is nothing in the display of VFD.

If it gets overloaded and faulted, how can I correct for that? What would be the way to start the blower again??

I tried to put a limit function in the ladder logic program. I could save it, but when I tried to go online a message pops up, asking to create new file or browse for the source file. If I create a new file, it shows as ML 1100 instead of the original file name. If I browse it shows me the folder name only!!

I am so ignorant in this issue !! What would be the best way to learn this types of things in general ??

Thnaks,

Get your boss to send you here: PLC Training Boot Camp

. If I press the contactor manually, the blower starts working. But it stops when I release the contactor.

Click to expand...

have you checked to see if there is voltage present at the coil? have you checked out the coil?

anik said:

But now, even it turn it manual, the K10 relay indicates yellow and there is nothing in the display of VFD.

Click to expand...

Why? Is the VFD display dark?

which output is tied to the coil?