Need help with control panels.

[alanmcm]

Is there anything out there to help me get my head round control panels and control circuits. I was stuck at a job trying to get a metal barrel press to work automatically. Press start button, press comes down, squashes everything, pressure switch activates and it comes back up and hits the limit switch to stop the cycle. Best I could do was to have it working without even pressing a button but it would go up and down at will, unless the door was open, limit switch through the e-stop.

Had to leave as a manual job, hold start button in, install new limit switch at bottom of press so they cant hold the button in for the pressure to keep building. Then another button to bring the press up to hit the top limit switch and stop there. Pump would still run if holding the button in but if at either limit it wouldnt move, unless in the opposite direction.

Im sure this is a basic circuit with a relay but Ive never built a panel before and would like to learn a lot more. This hurt my head and frustrated me and I dont fancy going through it anymore, I need more knowledge.

Thanks

 

[westward10]

When it comes to corporate manslaughter I think it does matter although there could be multiple factors in play.

 

[alanmcm]

Thanks for the replies, seem to have opened a can of worms. The press worked by pressing the start button and doing one cycle, changing it to a manual way of lowering and raising surely shouldnt make that much of a difference? Theres limit switches on the door, at top and bottom and also a pressure valve. If you let go of the button everything stops, all safety switches are in place as well. I work for a contractor and to get someone to sit with me to teach me is near impossible.

I was only trying to find ways of being able to learn more about things so I get a better understanding. Another guy helped me getting the press to work this way, all interlocks are in place, run lights, top and bottom limit switch light. If I have missed something could someone point it out so it can be rectified.

 

[alanmcm]

Best option, get the maintenance Electrician involved to give yu some pointers, if there is one that is.

Theres no maintenance spark on site. I did get help from another guy in work who works with panels. But we couldnt suss out how to get it working as a single cycle button press. More brain power needed, more knowledge needed on my part, hence why im enquiring here as to how others learned and what sources they used.

 

[Pete999]

Theres no maintenance spark on site. I did get help from another guy in work who works with panels. But we couldnt suss out how to get it working as a single cycle button press. More brain power needed, more knowledge needed on my part, hence why im enquiring here as to how others learned and what sources they used.

Hi Alan
With all due respect to you for wishing to learn and better yourself, the company you work for should not have let you loose on this machine unsupervised, training courses for these machines should have been made available to you.
I'm not personally experienced enough with manufacturing machinery to form an opinion on what and how to fix the faults liable to be found on these machines.
Others may have differing opinions, not really your fault but as a trainee, do you think it was right for you to go digging around in something you have admitted you know very little about? just glad that there were no injuries, don't know what the company manufactures, but not to have a maintenance Electrician on hand seems a bit remiss of the companies policy, good luck.

 

[Darkwood]

@alanmcm
Like has been mentioned, you are undertaking work that you are not competent to do, your willingness to learn commendable but this area of the industry is heavily regulated, a simple act of added to or changing the function of a machine/control requires a full risk assessment, what may seem trivial in alterations can have requirements that require new safety measures and systems to be put in place.
Even the simple addition of extra actuators like a few E-Stops to a simple DOL starter for a motor can require the whole control system to be redesigned so as to comply with the relevant standards.
The minute you enter a control board and make alterations and/or additions you take on board the responsibilities that said machine is safe to use, meets current regulations and has all the documentation and risk assessment that comes with the work you did, if you work for a company and you are been asked to do this then you must make it clear to them that you are not competent in this field and you have no qualifications to show you have had the training.
If you are ever in the unfortunate position to be pulled into interview due to an accident on a machine you worked on, you will be required to show your competence, show how the machine operates and how the safety features of the machine work in conjunction with the operator, if it is found the risk assessment falls short, the machine has been illegally upgraded or repaired then you will not have a leg to stand on legal action may be taken directly on yourself and/or the company you work for.

In the past the company I use to work for was caught up in such a scenario, we had to show how the safety system worked, what safety level it had been placed under and we also had to show them how why we thought the operator get injured also why and how the safety systems failed to prevent this... lucky for us we had complied and assessed the system correctly and we showed the operator had used ladders to climb over active safety barriers, opened a ducting panel using a tool and tried to unblock ducting while the machine was running, he failed to realise the fan blades spinning at 1500rpm may come in automatically! The said company was given a very large fine for not training it's operators properly and allowing routine breaches of safety, the point I am making here is you need to know your stuff from the the associated regulations, how to risk assess a machine and know what level of safety it will fall under before you even consider trying to work on it, the closest you may be able to go is to replace a like for like part due to failure where you have made absolutely no changes or additions and again if the machine is unsafe even ignorance can come back at you if anything were to occur.

 

[Darkwood]

Here is a free download, a sample of what is expected of machine safety and risk assessment, hopefully you will have time to browse it and realise why you may be digging yourself a hole you cannot get out of.
http://www.schneider-electric.co.uk...nt-manufacturers/pdf/Machine-safety-guide.pdf