Operators that don't know their systems

Hey everyone,

Please share stories that you may have of operators, not knowing how to do their job, my most recent one was on a service call where a plc lost its program, so once i downloaded the backup copy of the program that the customer had, line is back in operation, or so i think. The operators did their basic checks to see if the line is functioning properly, but wait, the operator tells me the line is not starting the start push button was not starting the system and it was definitely a problem with the program. So i decided to check the program, but to my demise the program is uncommented and had indirect addressing with shift registers all over the place. instead of trying to debug the program which will definitely take hours i decided to see where the start pb was wired to into the plc because the plc was a micrologix 1500 which had embedded IO, so i traced it through the program and it seemed that only two permissive where not met, so i ask them are they forgetting to press something, and bingo, the operator forgot to hit a acknowledge button on the HMI, so now the machine starts, but their is still a problem. The machine is a labeler that rejects bottles if they don't have a label based on a vision system, so the machine was currently rejecting early, so now they bombard me and tell me it is a plc program issue, i tried to tell them that the program has not changed, and that it was not an issue with the plc. Then roughly 2 hours later of trying to troubleshoot the program which was a nightmare, an experienced operator comes and sets the delay time on the reject, problem solved. The other operators look at me with a little embarrassment. Please share your stories im curious to know what some of you have faced over the years

Humor is always at someone else's expense.

There are better and worse operators, just as there are better and worse engineers and plant managers. A good relationship with a good operator can be an asset to an applications engineer, but I've known many plant managers and engineers over the years who were too damned arrogant to take advantage of that resource.

This one has nothing to do with the PLC, although there was one on the machine.

I had just driven to another city and set up for a three-day intro to PLC programming session I was teaching. I checked my voice mail and there was an urgent message from a customer who needed to get a machine back into production. "The operator pushes the start button and nothing happens. There aren't any fault messages on the HMI." I called him back to tell him I wouldn't be available until Friday.

Friday morning I arrived at his plant, he met me at the reception area, and we started to walk to where the machine was located. I suggested that he should probably bring some tools so he detoured to his maintenance shop while I continued on to the machine and got there before him.

A few minutes later when he arrived, I was holding the problem in my hand. It was the broken timing belt which I had found lying on the floor underneath the motor.

@ Steve, i bet his face was priceless

I converted our Fredrick smoke/steam house over to PLC control. After months of the system working flawlessly then all of a sudden it started having "issues". Of course it had to be the PLC program, so they called me into work early to resolve it saying the program changed. They were trying to steam product with the manual steam valve to the oven turned off. Another time they were not getting natural smoke in the oven, the burner was out of wood chips. Again another no natural smoke, the lid to the burner chip hopper was off stopping the auger, solution, put in a light to let them know the lid was off. On other steam ovens I converted, not starting, the system was not reset after the last batch. These are still ongoing issues, every month or so it repeats. When people ask where I work I just reply, Kindergarten.

Hi

Mine was a few years back now before remote access.
I upgraded a wrapper from relay control to a plc. The machine was wrapping milk bottles. I was working on site about 4 hours away and I got this call that the wrapper had stopped the the plant tech had been at it for hours and that it was down to the plc. The manager was not happy and told me to get there ASAP or the company I worked for at the time would have to pay for the overtime to get the milk out that day. Been a lot younger and greener I hit the road quicker than I should have and hit there in a little over 3 hours. I was rushed into the machine and the first thing I did was look into the panel. Straight away I saw the safety relay was not reset. I did check the e-stops that were at the front if the machine and they were all good. I don't know why I asked the question but I asked the operated what was he doing when it stopped. He went around to the back of the machine and said he was just bending over to pick up some bottles and there was a new e- stop button fitted by the plant tech and the operator had asked for it. I reset the e- stop then reset the machine and away it went. The plant tech just walk in with the manager about two min later and was ranting on about not having the plc software to go online and that the program had to be wrong as the HMi was showing an "E-stop fault" .
After at the manger let me have it I showed the operator, tech and manager what was wrong and i had not even powdered up the laptop. The tech then went through the drawings and said well that was not in the drawings and how could he know about it then the operator said well You fitted it last week.

I just picked up my tool box " which I had not even opened" and laptop and heading to my van. The manager came out and told me to put down a lose wire on my report and I just looked at him and said that was fine but did he understand I had a 4 hour drive back to site and that I would have to work late because of a lose wire. I also told him I had my boss down the phone to me ever 30 min asking me was I there as the manager had been on to him. He just looked at me and said send in the bill.

That said it all to me about good and bad operators, managers and techs .


Donnchadh

many years ago I had one of those bosses,(engineer), that come out to the machine and then instruct you on the correct method of fault tracing.
He would not let you explain what you had done already.
SO the fault descripion:-
Main 75Kw motor/star delta start occaisionally tripping out.
500ton mechanical press with a 10ton flywheel load.
Note:- usual test procedures carried out voltage current etc.
the engineer arrives: - he demands the following steps
1 - have you checked power - let me see you do it!
2 - have you checked the contacts of the contactors - take the arc shields off and let him see
(power down M/C then power back up)
3 - now start the motor - (I warn him to watch his eyes)

The result - the motor trips on load and the flash blows 2 x 240Amp fuses
engineer - motor must be no good - he runs off to organise a replacement.

what do I do while he is away
1. isolate
2. change the fuses
3. replace the arc shields
4. replace the faulty Star/delta timer (I knew it was the fault before the engineer had come out)
5. powered up the machine and ran it.

The engineer never spoke to me like that again.
D..KH..D

I usually have trouble with maintenance people.

Most recent was on an old machine we converted from relay to PLC.

I get a call from maintenance saying the machine won't cycle.

He said they were beating their heads against the wall for two hours trying to figure out what is wrong.

Naturally, I assumed they checked the HMI for problem conditions and faults.

I didn't have enough inputs available to do the blown fuse thing, so I asked if they checked the fuses? Yep, all OK!!

Told them I would be right over.

Drag all my stuff in and park it by the machine.

Go touch the screen to turn the backlight on and got a surprise!

Called the two guys over and pointed to the screen. Hey guy's, what's that "BOLD RED WARNING" say???...

...Low way lube level?, Yep!!!

They said they saw that but it never registered

Go fill er up and see if she cycles.

Bingo!

very interesting guys keep them coming

I enjoy funny stories. I could tell a hundred about similar situations. After many years of reflection, I think that 95% of the problems found in this type of owner-programmer-operator interaction story are caused, one way or another, by poor communications.

1. The owner did not write clear specifications that said exactly what he expected the machine to do, so the programmer worked in the dark until near the end when he was able to start the machine and see the problems first hand.

2. The PLC programmer did not develop an outline of his proposed program to give to the owner, with step-by-step descriptions of how he proposed to write the program. No one at the customer company knew what was in the black box until it was delivered.

3. The HMI programmer did not use clear labels on his controls. Some operators could figure out how to run the machine, others did not understand some of the steps. There were buttons labeled "CLOSE". Close What? Stop What? Start What? The process consisted of steps, but no where on the control panel did the operator know what step the machine was performing. This type of mis-communication leads to maintenance problems.

4. There were no overall graphic schematic of the process, so most operators did not have a clear idea of the whole process, but tried to limp by with inadequate knowledge. Training was poor to none, with old guys quitting and new guys coming in with a 5-minute instruction session followed by "you will learn on the job in no time at all".

5. Changes and revisions were made from design start up until the machine was started up. No one had a clear idea of all the changes, as the operators were trained based on the original program that had been changed a hundred times.

6. The machine did not have a good user manual, with clear instructions and directions. There were very few drawings and diagrams.

Lack of commmunication, poor commuication, lack of understanding of the existing instructions, poor training, and such can be summed up as 95% of the owner-programmer-operator problems. The other 5% are really the easy part to solve: the machine malfunctions. Solving the big 95% means that a bunch of people are going to have to learn to talk to each other.

Then roughly 2 hours later of trying to troubleshoot the program which was a nightmare, an experienced operator comes and sets the delay time on the reject,...

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Why did the other operators not know about the reject delay timer? You got it: poor communication. For some reason, the people who knew about that timer did not think it important that all operators be instructed about its function. Ideally, the instructions would be included in the HMI panel program.

I have too many of these to list, so instead how about operators that know their machines too well.

1. Radio call from ops manager, "Hey Paul, did you know about the new 'brand x' packaging?" I have to program the robot(s) to stack it, and add reader and weight data for the sorter/checkweigher. This happens too often here. Product designer and packaging and purchasing all must be involved because these changes are a big deal. In the chaos they sometimes forget to let me know, and then ops ends up hand stacking for an hour while I get the new stuff set up. Most of the time its done in advance, but not always.

Manager: "Our Ace Operator says he figured out how to make it run so take your time. getting back there"
Me: "?" How can he do that, the barcode isn't in the system, no robot unit load?
I gather the information and tools and go back there and Ace has cut out the barcode label from an old box with a pattern in the robot list that is really close to this new one. He taped his barcode cut out to the conveyor frame in front of the redundant reader which is after lane 1 so only the new product would always be read as the old code and sorted and stacked pretty darn good. Genius.

2. Hey Paul, your new logic has a problem...(this is on a long steel belt fabric converting line.) I get over there and the operator is at the gum applier station about the middle of the machine. He says, if I put the appliers in manual, hold the jog button and stick my foot in front of the loop sensor the upstream belt runs backwards. It shouldn't do that. I know that it would be really unusual for someone to do this, but I thought you might want to fix it anyway. This guy, although known as a squeaky wheel, sort of a crybaby, was invaluable. If he ran my machine for a week without uncovering a new bug, there were none to be found. He would try every possible combination of jacked up knob dickering conceivable. It was like he was playing playstation trying to uncover a hidden level, which he occasionally did.

My story goes like this:

Several years ago I was working for a small electrical company who looked after lots of local companies.
On a Saturday morning my boss asked me if i could go to the site as they were "having problems with their robot". At the time, I knew nothing about robots but agreed to go as it was only an hours drive.

On arrival I was told the story. The operators came in at 6am but couldn't start it, so they got the manager out of bed and he couldnt start it either.

"It's just like there is no power" they said. I quickly put my meter on the live side of the panel isolator and sure enough it was dead.

I followed the armoured cable back to the wall mounted isolator switch and it was off!

"Yes, but we never switch that one off......." They told me!!!!


I will agree GOOD operators can save you a whole lot of time. I usually ask them "What should it do when..?".

BAD operators say "It won't go" Even I can manage to work that out by myself!!!!

I usually have trouble with maintenance people.

Yes, I get this to! I work with one tech in particular who's lack of logical thought worries me!

Sometimes the failure to communicate is caused by legal, political, or status issues, as illustrated by the attached story.

OkiePC said:

I have too many of these to list, so instead how about operators that know their machines too well.



He says, if I put the appliers in manual, hold the jog button and stick my foot in front of the loop sensor the upstream belt runs backwards. It shouldn't do that. I know that it would be really unusual for someone to do this, but I thought you might want to fix it anyway. This guy, although known as a squeaky wheel, sort of a crybaby, was invaluable. If he ran my machine for a week without uncovering a new bug, there were none to be found. He would try every possible combination of jacked up knob dickering conceivable. It was like he was playing playstation trying to uncover a hidden level, which he occasionally did.

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that is pretty hilarious, playing playstation trying to uncover a hidden level, good one