Manuals

No, I'd rather teach you to use the internet to find them yourself.

You can type "allen-bradley" in a search engine and you'll find the rockwell automation website. Once there, you select the Allen-Bradley brand. Then click on "Literature Library" and then on the "+" infront of the Programmable Logic Controllers. Find the "PLC-5 System" and click on it. You'll get a list of manuals, installation guides, selection guides, a whole library's worth (okay, I'm exaggerating ).

I hope you think of coming back and registering. You seem to be thinking of just popping in, leaving a question and an email address and then wait for someone to send you a message. That might happen, but then again, it might not. Besides, I think you'll find that you'll get more out of being a member than just a guest.

Watta ya think?

regards,

Vulcan

Thanks for your sugg., but i have already done that. but,i found nothing related to my problem. we have a boiler having capacity 5 tph, PLC of Allen Bradely model SCL 500(5/03). Fuel pumps tripping regularly, when try to run the boiler.we try everything like pressure switch resetting,bypass connectins,conactors are ok.Checking fuel level in FO(fuel) tank,Temp of fuel is right Ringman pump generating fuel pressure accurately.Safety is ok. anybody know somthing about this?

I'm not AlBrad user, but I'm supposing all controllers based on the same principles. Do you have access to source code(ladder diagram) for analyzing what could cause a trouble?

You said "Safety is ok". Is one really ok? In case of current leakage(which could be measured by controller or other device) it's likely causing a problem in sake to protect personnel. Is the wiring, sockets dry, i.e. free of condensed water? Check out earthing(grounding).

I guessed there's a pump tripping without any alarm signals or so.. Yes, "interlock" just a proper word to describe the most feasible reason.

Thanks for help guys,i really appreciate u Mr Vulcan and Mr Cramba.i think,i messed up the things.actually i am not an electrical guy,i am a mechanical engg. and i am looking utility operations and maintenance to some extent in an 'API' pharma plant.

actually everything get operated comfortably in manual mode but not in auto mode, thats why i am not concentrating on electrical solutions.Now,we are able to operate these things some how through PLC.But we have not yet able to operate variable frequency drive,ABB 'ACS 800'(operating pumps,blowers according to the required load) in auto mode with PLC.We have to switch on the drive manually(separately) after the PLC start running.

we have two different loops(two fuel supply pumps attached to the same supply line) of fuel supply to boiler.we installed a new pump today.But, when we circulate the fuel through this pump without switching on the burner of boiler,it generate pressure without any problem and when we switch on the boiler burner,the fuel pressure starts varing(up/down) very fast. i am not understanding this problem.

All this starts when one of our electrician try to replace one damaged contactor of OPH(oil pre-heater) in running condition.

Now i am a registered user of CR4.

Thanx and Regards,

Gurvir Singh 'Punjab'

Welcome Punjab,

It would be difficult to solve your problem over a forum since no factory is the same as the next factory.

Do you or your people know how to troubleshoot using the PLC program? By that I mean, can you find out what interlock is needed before the drives are started up?

Also, it may even be that the drive's controls are designed that way (start manually after switching on the PLC). Only your electrician (if he knows PLC programming) will be able to find out.

This is not to say that mechanical engineers can't learn how to program PLCs. We had one such person in the company once. He understood instrumentation and controls in addition to having the ability to program PLCs and HMI. We were pleasantly surprised to learn that he was a mechanical engineer. Nowadays, instrumentation and PLCs are the domain of electrical or electronics people so having a mechanical guy understand our work was a welcome thing.

Fuel pressure fluctuations upon burner firing can be due to several things.

Is your fuel filter dirty? Is your fuel pressure control device constantly adjusting? Is your fuel dirty? Could there be a linkage that's loose? A solenoid valve that's chattering? There's a lot of possible reasons.

Just one more thing. You mentioned that your electrician replaced a contactor while the boiler was running? I'm not sure if that's safe to do. In any case, if the pre-heater was turned off while the burner was running, you may have allowed thickened fuel to get into the burner's innards. Maybe you should take it apart and clean it.

I think you have a lot of troubleshooting to do. However, if you know how your boiler works, try to think of what can cause the symptoms you're seeing. Then eliminate the possible causes by testing each one at a time.

regards,

Vulcan

Thanks for all of your help.

Regards,

Gurvir

In addition to what Vulcan said, I suggest you'd think throughly before be involved to dig in what you hadn't been authorized to do (PLC programming and tinkering).

If someone contractor had installed PLC controlled system it'd be better the same contractor being called to shoot any trouble on your plant process.

There could be a lot of reasons why fuel pressure is pulsating. The only thing you can do is to check out mech and electrical parts for assurance all is ok there then invite someone who really have a skill for PLC programming to sort your problems out.

By now, if you have any way to keep your facility running under semi-automated or completely manual mode, just keep it running this way.

The best thing is an enemy of the good one.