RS logix 500

I have an assignment and I need 3 more answers. what problems you encountered during the design of the program and describe you used to eliminate these from the final program.

3 MORE answers? What answers have you already come up with?

mandy said:

what problems you encountered during the design of the program and describe you used to eliminate these from the final program.

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I am willing to help, however I need some more information to be able to do so. Therefore, please describe as detailed as possible:
What problems you encountered.
How you eliminated them.

Problem: Couldn't get motivated to write the program.
Solution: Went down to the corner and bought some crack to help motivate me.

Problem: At startup I realized the program seemed to be written by someone on crack.
Solution: Called the boss and asked for someone competent to come assist.

Problem: The plant manager was screaming and yelling about startup delays due to program errors.
Solution: Shared my crack with him.


I could come up with more but I have to get motivated to write a program that needs to be started up in a few days.

Q: what problems did you encountered during the design of the program?

A: I went to an online forum and asked someone to do my homework for me. The forum members refused and said I should try and do something myself first and show my work, then they would help me improve it.

Q: Describe how you eliminated these problems from the final program.

A: I took the forum members' advice and tried some answers on my own. Then I found them to be most helpful in critiquing my answer and improving the final answer.

Alaric said:

Q: Describe how you eliminated these problems from the final program.

A: I took the forum members' advice and tried some answers on my own. Then I found them to be most helpful in critiquing my answer and improving the final answer.

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Won't happen! That would mean work on someone else's part. Just wait long enough and maybe someone will do it for me. Or, go to other forums and ask the same thing.

LOL thats great !

jtn said:

Problem: Couldn't get motivated to write the program.
Solution: Went down to the corner and bought some crack to help motivate me.

Problem: At startup I realized the program seemed to be written by someone on crack.
Solution: Called the boss and asked for someone competent to come assist.

Problem: The plant manager was screaming and yelling about startup delays due to program errors.
Solution: Shared my crack with him.


I could come up with more but I have to get motivated to write a program that needs to be started up in a few days.

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brucechase said:

Won't happen!

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Experience tells me you are right. But I keep hoping the hints will skink in.

Mandy, we're happy to help and mentor you. But you must understand that we all expect to be working along side you our your classmates some day, so surely you can appreciate why we want you to make an effort for yourself.

I have a plant shutdown tomorrow where I will have to test and calibrate 10 13,800 volt breakers, 30 electromechanical relays, 15 13,800 volt load break switches, 15 2500KVA oil filled transformers, 70 480 volt DS breakers and I only have 10 hours to do it.

Can someone tell me what I need to do before tomorrow morning? It's not homework, but it is due tomorrow.

Gee I hate to sound stupid, but how do you calibrate a breaker?

I only work up to 500 volts

Clint

To calibrate circuit breaker.
Have known voltage and resistance (load) sufficient to trip breaker. Install current measurement and timer.
Energize
measure current and time elapsed.
Compare current and elapse time to trip curve.

OR
Buy Multi Amp circuit breaker tester. Two versions 100 lb and 3,000 lb.
I only toted em around (forklift was handy for 3,000) and used em -- did not have to buy so dont know price tag.

Dan Bentler

Bruce

Round up all those lifting bars that have been gathering dust. Dig out all them funny crank handles everyone wonders about.

Get a whole bunch of flashlites.
Maybe a generator or two and DEFINITELY some propane area heaters. You are gonna get cold.
If you have only 10 hours round up a whole bunch of bodies.

leitmotif said:

Bruce

Round up all those lifting bars that have been gathering dust. Dig out all them funny crank handles everyone wonders about.

Get a whole bunch of flashlites.
Maybe a generator or two and DEFINITELY some propane area heaters. You are gonna get cold.
If you have only 10 hours round up a whole bunch of bodies.

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WOW!! How many of these have you done? I would swear you are working beside me. 10 hours and all the power is on. One plc program lost (low battery) and 1 gateway to reboot. I found about 1/2 of the funny crank handles that everyone wondered about. With 25 guys and 15 stations, we had to share too many. Will have about 15 on order before the next. Not too cold here in SC right now (about 58F), but had 1 250 KW gen (for the 2 3000 pound multiamp test sets) and 5 5000 watt gen. Lots of lights and vacuum cleaners and a whole bunch of ground clusters. Not too bad this time.

Gee I hate to sound stupid, but how do you calibrate a breaker?

I only work up to 500 volts

Clint

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Clint, you don't sound stupid. All of the breakers we tested are 480 VAC. The big 13,800 volt breakers are really just switches. There is no smarts on them at all. The protective functions are acutally relays mounted on the cubicle doors. That sends a trip signal to the main breaker. The 480 VAC breakers have the smarts built into them. These are done exactly as Dan described. It sounds like he's done more than he cares to remember. There are actually 2 ways to test/calibrate the breakers as Dan describes. The big test set is actually primary current inject into the stabs of the breakers. Yes, 20,000 amps are injected into the breaker to verify it trips. The second way is secondary current injection. Here, the signal is put on after the CTs (built into the breaker) and only 30 amps are required to trip the breaker. I actually prefer to use primary if I can.

Hope this helps.

By the way Dan, you did give me the answer before I actually had to do the work. Does this mean you (or I) will have to give the homework answer if asked. I was actually trying to be a smarty pants and show some of these students that no everyone will do the job for you just becasue you don't know it and don't want to take the time to research what needs to be done. Just give me the answer so I don't have to think.

Well,

Is this something that should be done regularly? I have worked in Maintenance departments for 20 years (started picking up the trash) and have never done this. Or are you guys working in some kind of special type of plant?

Clint

Clint,

Yes, if you have several of this type of breaker or switch and you want your plant to have reliable short-circuit protection, then you need a regular periodic test of the tripping mechanisms. If you never test them, there is no way to know if they will work when needed. If these tripping devices are needed, it will be in the worst possible situation and it will be much too late for testing then.

I am sure most of us have heard of or experienced a case where the plant main breaker did not trip when it should have. It usually results in a pile of metal slag in the electrical room.