PLC Test

I will have job interview with test for Industrial electrician in Paper Mill. Can any one know what would be the typical test and question in connection with PLC? What knowledge level I have to have? Thanks

Your knowledge level will be whatever you have. Learning the answers to specific questions won't show any type of working knowledge. If you can't provide the answers from what you know then you aren't at the level they are testing for.

That said, there is 'Learn PLCs' at the top of this page. Go there and brush up on general knowledge of PLCs. Having the level that the course teaches should at least get your foot in the door.

Greetings bedast ...

and welcome to the forum ...

I completely agree with my distinguished colleague, Bernie ... knowing the subject is much more important than just being able to answer a few questions on an interview ...

but then again, sometimes a man's gotta do what a man's gotta do ...

so what's your deadline on this? ... also, is there anyone (friend of a friend, etc.) who might be able to tell you what brand and model of PLCs this particular plant is using? ... IF (that's a big IF) you have enough time available to invest in this project, it would be VERY helpful to know where to concentrate your efforts ... don't get me wrong – ANY knowledge is better than NO knowledge ... but if the plant uses only Allen-Bradley PLC-5 systems (just for a specific example) then I wouldn't spend my limited time and energy studying some other brand or model ...

based on what you've posted so far, (and assuming that you have very little time available) I'd personally suggest that you spend some time and effort learning how the LEDs on the front of the I/O modules work ... for an "industrial electrician" those little jewels are usually the most important "check this first" area when it's time to troubleshoot ... if you can't demonstrate (at least) a working knowledge of how to interpret THOSE, then I'd say that the interview isn't going to end up very well at all ...

I wish we could be more help ... maybe if you could give us some more specific information, we'd be able to offer more detailed advice ...

good luck – and we hope this works out for you ...

Thank for sending me to courses. I’m sure I will take some if I’m hired. I design controls for thirty years and wire PLC for 20 years. But I did programs only on couple older makes Modicon and Square D.
My question more specifically is what I have to rely knows now to get the job. Did someone went or have knowledge about the expected or required knowledge level for industrial Electrician?
Do I have to know to select the timer and what minimum increments I can use and what happens with different PLC Models and different type of scanning?
Or haw to transfer A-D data from memory?
Or do I have to only understand how to install additional LS to reversing starter?

Thank for sending me to courses. I’m sure I will take some if I’m hired.

Click to expand...

I'm not sure I understand that statement – but just to clear things up, I'm NOT suggesting that you take one of my courses ... actually I don’t actively market these to individuals – only to companies ... I'm just offering you some friendly (and free) advice here ...

My question more specifically is what I have to rely knows now to get the job. Did someone went or have knowledge about the expected or required knowledge level for industrial Electrician?

Click to expand...

I think I know what you're asking for – but I can honestly tell you that the job title "Industrial Electrician" covers a LOT of territory ... one plant expects ONE thing – while another plant right down the road expects something COMPLETELY different ... in SOME plants the "industrial electricians" NEVER go online with the plant's PLCs ... but in OTHER plants, guys with the very same job title actually do make changes to the PLC programs ... trust me - I'm not trying to give you a runaround here – but every plant can be different ...

once again, my advice is to track down someone who works at the plant you're interested in and ask some friendly questions ...

Im an industrial electrician and i work in a paper mill in sweden.
I am the youngest one there by 20 years so my job has been put towards being the plants PLC expert since i have the most recent knowlage from school (im 24yo).

Where im working we have two types of technicians, one is instrumental technician and the other is electrical technician but we all go under the name of industrial electricians since everyone of us should know the basics of everything but have specialties with larger knowlage.

The instrumental technicians are specialist at regulation control and the instrumental controllers.
The electricians are more toward just electrical stuff like motors and such.
Im a hybrid of these two but specilises in PLC and control systems for motors.


Since you are looking for advice on PLCs im guessing your applying for job in the PLC department.
If i have to guess i would say that you will be mostly used for troubleshooting the machines wich would require a more general knowlage of how PLCs works and how to read the logic.
If you know one brand of PLCs the steps for learning a new one is rather small since they are all designed for roughly the same things.

So i would say that you need to learn the logic of programming a PLC regardless of brand just to get an overall knowlage since there are allways manuals to read and people to ask on more specific issues.

I hope this answer has given you anything

ojz0r said:

Im an industrial electrician and i work in a paper mill in sweden.
I am the youngest one there by 20 years so my job has been put towards being the plants PLC expert since i have the most recent knowlage from school (im 24yo).

Where im working we have two types of technicians, one is instrumental technician and the other is electrical technician but we all go under the name of industrial electricians since everyone of us should know the basics of everything but have specialties with larger knowlage.

The instrumental technicians are specialist at regulation control and the instrumental controllers.
The electricians are more toward just electrical stuff like motors and such.
Im a hybrid of these two but specilises in PLC and control systems for motors.


Since you are looking for advice on PLCs im guessing your applying for job in the PLC department.
If i have to guess i would say that you will be mostly used for troubleshooting the machines wich would require a more general knowlage of how PLCs works and how to read the logic.
If you know one brand of PLCs the steps for learning a new one is rather small since they are all designed for roughly the same things.

So i would say that you need to learn the logic of programming a PLC regardless of brand just to get an overall knowlage since there are allways manuals to read and people to ask on more specific issues.

I hope this answer has given you anything

Click to expand...

Thanks this help

I'd suggest that you are up-to-snuff on the electrical characteristics relating to a control system. A control system will have:

- 24VDC/120AC voltages
- 4-20mA/0-10VDC control loop signals
- Field device setup/calibration (RTDs, Flowmters, Pressure Sensors, prox switches....)
- How does grounding impact analog signal quality?
- Communication physical characteristics (generally speaking) such as Coax cable - ControlNet, Purple cable - Profibus, Blue Hose - RIO or DH, Ethernet....yadda yadda.

Typically if a system is running, and something goes wrong 90% of the time a component has failed in the system, NOT the program! Therefore I would be more concerned with demonstrating your skill set at identifying and correcting those component failures then worrying about working with a PLC. Personally if you have PLC experience I would see that more of a "bonus" rather then requirement, however you would have to post the job description.

Previously I was a "Controls Technician" in a manufacturing plant, I had zero confidence in our "Electrical Technicians" ability to go-online and use the PLC program to troubleshoot, they had training, but you don't use it you lose it. I had experiences where a memory bit/IO address was simply "Forced" into the state to make the system run, rather then fixing the actual problem.

Anyway, that's my advice, hopefully it is of use.

I wish you the best with your interview; but you have to feel out the company a little to see if you are going to be a good fit for them and the job a good fit for you. I work with a person that was a controls technician with another company. When he first started, he wanted to know everything about the machine we were working on at the time by asking a lot of detailed questions; unfortuanly time is money and our management wanted the equipment up and running ASAP, so there was no time as they were concerned to explain things in detail to him while on down time. He would overanalyze things before doing anything; I would have to jump in and get the equipment running by letting him know we could talk about it later. The company we work for likes quick reaction time with quick results; so its start with simple then work towards harder solutions, which saves a lot of time in almost every case. This person is probably very good when working with engineers to design a control system then install it; but not very good at fast troubleshooting electrical/ electronic equipment. He was trying to trouble shoot a machine by using the lap top hooked to a PLC ; I was standing back to see how he was doing and a supervisor told him to let me in there because he was taking too long. With the schematics, I found the output in question and went through the program searching the inputs that had to be true to make the output come on. The problem was found to be a bad sensor that was lit up but not sending a signal to a input that in the program would start a timer that was not telling a internal bit to come on after it timed out which was suppose to latch the output coil on in the program. It would be great if every company would take the time to go over every aspect and detail of every machine so all techs would have a great understanding of how a machine works before they were expected to work on it. I am not sure how other companies do it, but the company I work for has the attitude to try to fix it and if you can’t figure it out fast, ask for help then pay attention to how it was fixed so you can learn something about the equipment. What I am trying to say with all this is please find out what they expect from you; to hit the floor running or maybe they have a training program you will go through; but I am sure most companies want people who have experience to fix things for them with little training. Go to your interview with a positive attitude and try your best on their test. Most companies have a written and hands on test because so many people are book smart and can interview well but have trouble with the hands on repair. I do wish you the best in your job search; but make sure this job is going to be right for you and your experience because a company really does not care what a person knows as much as what they can do for them to get production back up in no time. I hope this helps. Let us know how the interview goes and if you get the job?

Sincerely:
Maintenance Man

Just another thing to think about ; a paper mill is a very large place so I am sure they probably have the maintenance departments broke down in to General maintenance mechanics which do the greasing , oiling of chains , changing bearings, gears, pulleys and other parts as needed. The Millwrights that do the welding and fabrication of things used in the plant; this also includes the machinists. The plumbers (pipe fitters). The electronic techs/scale techs who are going to take care of the PLCs, scales , control systems and other electronic devices which will probably have the IT people working with in there department also. Then we have the Electricians which you are interested in which they might be responsible for only the electrical utilities ; so you might be installing conduit on the ceiling and through cement walls and floors, pulling cable and wires, wiring and unwiring motors and other electrical devices, pulling and installing cans, changing lights and fixtures, etc. Do you know what kind of industrial electrician this paper mill is looking for? Just something to think about.

Sincerely:
Maintenance Man