Losing voltage at E stop

[Knobhead]

I applaud your thread timing Ben....during Tony's afternoon nap! :smilielol5:

I'm awake now, unfortunately it's 02:00! I'm not even going to comment on this travesty. I just hope it doesn't develop in to a tragedy!

 

[wade88]

Yay Tony's here!

Brightspark, i did mount the tray on spacers, you just can't see them. As for the top bend, it's pretty ugly for sure. Bit of a tray noob, so ill do a better job next time.

Vaughant, thanks mate, i've got it down now, made a really silly error, really face slapping moment, but it's all good now.

Robostar, due to my lack of experience in this area, i didnt think to look to get a dedicated safety contactor, figured the one i have would suffice (which it will) although i appreciate it is not idea for the scenario, i will source a new contactor asap


Thanks again lads, really appreciate the feedback...and you tony, big kisses

 

[Spoon]

I thought one of your work mates was going to help with the design of this? One that has lots of experience in machine safety directive and safety circuits?
Again (just cause I curious and it is important) are the mesh guards on the mixer fixed (Bolted closed) or hinged (for maintenance)?
If there has been a full safety report and there is no chance of injury to people do you still need an Emergency Stop circuit? Could you just not use a Stop Circuit?

I quite understand why Tony is not saying anything.... I hope you are being supervised by your work mate who has experience in machine safety directive and safety circuits

 

[wade88]

My colleague is from a different company, he came down for a day to help me with a bucket lift conveyor i was having some issues with and then talked me through the design of this.

It's ok, i understand why people may be dubious to make comment, thats fine.

Bolted closed mate.

 

[Spoon]

Im just trying to help you out a bit mate and hope that you dont end up getting yourself into lots of trouble if things go wrong.
Its good that the guards are bolted closed.
When you did your risk assessment what Category of stop was needed for your design?

 

[wade88]

Yea and i appreciate it fella for sure.

Not really sure what you mean by category of E stop Spoon, like i said, new to this area, but i decided after writing the SOP for the process and scrutinising it, although i dont necessarily feel E stops are essential, if i am honest i weanted to put them in because i never have before and wanted to give it a go and couldn't see the harm in doing so, but i opted for standard, latching, twist reset E stops.

Again, I can only apologise that my threads may wind the veterans amongst you lot up no end, but i have no where else to turn for help on these matters than this forum quite honestly, and although thats a rather scary prospect and 95% of you guys wil have just sighed in desperation, i still feel that by coming here and asking my stupid questions, at least its better than not asking, not knowing what i am doing, and just doing it wrong..... wronger....

I am not a total plank, i promise, im quite competent, but there are many many things for me to learn, i am just trying to do that, albeit a little unorthodox.

 

[vaughant]

Yea and i appreciate it fella for sure.

Not really sure what you mean by category of E stop Spoon, like i said, new to this area, but i decided after writing the SOP for the process and scrutinising it, although i dont necessarily feel E stops are essential, if i am honest i weanted to put them in because i never have before and wanted to give it a go and couldn't see the harm in doing so, but i opted for standard, latching, twist reset E stops.

Again, I can only apologise that my threads may wind the veterans amongst you lot up no end, but i have no where else to turn for help on these matters than this forum quite honestly, and although thats a rather scary prospect and 95% of you guys wil have just sighed in desperation, i still feel that by coming here and asking my stupid questions, at least its better than not asking, not knowing what i am doing, and just doing it wrong..... wronger....

I am not a total plank, i promise, im quite competent, but there are many many things for me to learn, i am just trying to do that, albeit a little unorthodox.

Nothing wrong with asking fella but you will always receive some aghast replies as really in a control style apprenticeship like I (and no doubt many others in this section) did,the first thing you learn about any machine is how to stop it and then how to start it.
The safety circuit is always the first part of pretty much any control design because the idea being when you hit the "big red button" you cut everything off as you don't know in that split second whether there's a jammed hand,split hydraulic hose under pressure,burning motor etc,you just know you want the whole machine to stop there and then hence the importance of it and in all honesty it's good to see your trying to incorporate that into your work,but be aware there's a LOT to the safety side of it and there's some really clever bits of kit out there which make it safer for the operator which is what it's all about really.
In ford even the majority of bolted guards had limit switches on them directly linked to some sort of safety device as someone got crushed in another plant by opening a fixed door while the machine was running.
No safety system is 100% foolproof,but it's designed to make you think about why your bypassing it,which often you have to in a controlled environment,rather than just jumping in head first.
I think it's a bit like when the more installation biased sparks get very wound up when folk don't use the correct size earthing etc,I've found in most industries where I've worked it's a case of "use what we've got" rather than always using the exact for the job,often it tends to be larger than required but this is not always the case.

 

[Spoon]

Not really sure what you mean by category of E stop Spoon,

Have a read of this.
View attachment Risk_Assessment.pdf

 

[wade88]

Thanks guys. Spoon, thats great, i have printed that off and bound it into my H&S folder, i am attending a NEBOSH International Cert course next month, so that will definitely give me a good leg up on all of this.

The risk assessments i carry out are based around the guidance provided and templates available online at HSE: Information about health and safety at work as thats been my only point of reference since doing this job.

Good news it however, i just tested the circuit, and it all works fine. Start/stop, the main E stop, forward reverse and all my E stops on the hopper all work. So im pretty pleased with that.

Vaughant you are absolutely right on all accounts, i have no insisted at work here to have almost free rein on my own purchasing accounts so i buy what i want when i need/want it, to allow me to purchase the correct stuff for the job, as spoon has pointed out however and a few others, what i feel is right for the job, may be and often probably isnt, but what i have got this time is working, and it is all safe.


In time and as a gather more experience, i will pick these things up along the way i guess.

Thanks again everyone

 

[KAS1]

I remember when people would employee a design engineer to do the electrical design work (if the inexperienced trainee / electrician wasn't up to it) and then install the electrical installation to a spec lol

 

[KAS1]

If things go wrong on an install it's no good saying to a paying customer "well that's what I was told on a forum" does your customer know you're getting most of your information on here? even how to make a good job of traywork lol

- - - Updated - - -

If things go wrong on an install it's no good saying to a paying customer "well that's what I was told on a forum" does your customer know you're getting most of your information on here? even how to make a good job of traywork lol

- - - Updated - - -

don't know why that posted twice

 

[wade88]

It's not for a customer, it's an install at the company i work for. Im the plant manager here, but do all the maintenance, electrical and plumbing work. Well i do everything really.

Yes the tray work isn't brilliant, im totally over that, it's not affecting the operation of the circuit, ill get it looking nicer next time, and no i fully understand it's not ideal getting tips from a forum, but i'm not entirely sure what else i should do. For topics i am unsure about, i seek help where available, and, for all intents and purposes, i have now installed a safe and operational circuit after some guidance. I'm happy.

 

[KAS1]

sorry Wade I was getting misled by your link to a website I thought you were an electrical contracting company, my mistake, my advice would be if they've employed you as a plant manager why don't you contract the electrical work out to a qualified electrician? and then manage the contractors?

 

[wade88]

That (was) my company, don't work self employed anymore, but as the websites suggests i only did domestic jobs and event power, now i have moved into a more industrial environment by proxy i guess.

Yes some work is contracted out, so typically as a plant manager i would be managing the tasks to be completed by outside contractors, but because im fairly handy, i started to do everything my self, and then i ended up falling into the control side of things, of which i know very little. Everything else i am totally happy with, but since having been involved in PLC's and the actually operation of heavy machinery and their panels, i have for sure lost my way a little.

I am however, picking it up quite fast, and rest assured, and i am being more sincere, any jobs i seriously don't feel comfortable with, i simply get people in, that goes for everything else i do outside of electrics. But, electrics kill people, a badly soldered yorkshire joint on a soak away will just get someone wet, so i fully respect the difference and always have.

I think people here think i just dive head first into serious work with no idea what im doing...... *cough* ........ but i do honestly do as much research and reading and general background as i possibly can before i even get the tools out.

I do need to remove that link now you mention it.... not that its even done me any good lol! But i am just a humble plant manager now.

 

[Knobhead]

All I can say Ben, it must be a laid back plant to manage. Been there got the tee shirt and made the maintenance guys life a misery. I hadn't got time to go delving in to things. I'd got 50 guys to keep employed in some way or another. Fix that bloody plant NOW! or I'd have you shot at dawn!

 

[Darkwood]

Hmmm... i applaud your enthusiam wade but even with the advice give and links the risk assessment and safety side of a control system isn't something you can work out, learn or be competent to do in a short space of time, there are so many indepth requirements as well as positioning segregation and design of the control system that couldn't have possibly even been touched on here in such a short thread up to press.

Ive briskly wisked through the posts and il stand corrected but i see no mention of seperate reset in that resetting of the E-stop will not on it own re-energise the disabled circuit or control circuit as a seperate manual reset will be required to be operated to be able to start the the dropped out circuits.

I can recommend you pop into your local Engineering wholesalers and pick up the free booklets from the likes of Pilz, Schneider or rockwell....i have the rockwell catalogue on their control safety products and is a wealth of info although biased with their products as solutions it gives an indepth read-up on how to risk assess to find what safety catagory the machine falls under , relevant EN an IEC standards, examples of safety set-ups with wiring diagrams for each catagory and all the formulas for designing more advanced systems where distance to hazards need calculating in relation to safety detection circuits.

I know you won't take offense when i say you really shouldn't be entertaining designing your own E-stop systems with the help of a forum as too many questions and answers to ask and know about the machine and job and user interaction that could be possibly asked .

Tred carefully as no PL-insurance will cover you for this unless you have specified it within your duties to design and alter or build control systems, if you or your company has this clause covered in insurance you will probably still lose cover if it dosn't comply to EU Directives and regulations. If the worst case happened without such cover it could bring your company down.

 

[Knobhead]

Not worth the effort DW.

 

[majaya]

Have you checked your cables to earth? You might be having an earth fault or damaged cables.
Whats the source of your 24V?

 

[Darkwood]

^^^^^^^????????

 

[wade88]

Ok, aside from Tony's useful input and don't feel you need to come back with anymore helpful nuggets of wisdom here old boy im sure you have plenty of other people to go and wittle away at.

Aside from college, as i just can't go down that road for an array of reasons anymore, where and how is the best way to read up on the "regs" of such topics such as control circuits, industrial control and the like. Are there courses available that are recognised, and what is the best way to learn more. I have a lot of reading to do which some kind forum members have sent my way, and i am attending a NEBOSH course in a month as i will be taking over the SHE managers job role in the forthcoming weeks also.

Yes it is a small company, and yes for the last ten years it has been a self sufficient entity with no outside involvement in regards to maintenance and everything else. Repairs and new builds of gear have taken place in a very Heath Robinson manner but i was asked to come in and take over that aspect of things as well as over see the design and build of any new engineering projects we are undertaking.

I undoubtedly don't hold the experience many of you do, and undoubtedly have not "commanded" as many men as some of you either, led the charge through the breach at the Tea room 2 minutes before break time, or even shouted at a poor maintenance tech till he cried and curled up in the fetal position, but i have just started this career no more than two years ago, and have not had my hand held through the beginning of it so have done my very best to work things out for myself and do what i feel is best. I do my upmost to keep safety as a priority and yes, as pointed out, sometimes get it wrong or have done things in somewhat of an unorthodox fashion, so i come here to get a little steering in the right direction, not to highlight my incompetence for the pleasure of the vultures here who love to take people apart for a good ego massage.

This forum has fast become more of an executioners social club, where people wait for "silly" questions just to run in swords drawn and hack the poor bugger to pieces. But in my opinion, better a stupid question asked and a person leaves understanding, then no question asked at all. So i fully intend to just keep on asking.

For those of you who deem me to not be worth the effort, thanks for coming this far but by all means do one. But for everyone else who has personally gone out of their way to help me, i appreciate it very much.