Ethics of modifying PLC programs on unsafe machines

Correction:

Quote:
Originally Posted by ojz0r View Post
There are no inches in the civilized third world, only meters

Canuckistan reporting in... though I admit I'm reasonably fluent in both standard and science units of distance and temperature, still working on the less commonly used units of pressure and such.

Regarding the original post: If you cannot reasonably remove any safety issues you find, you shouldn't touch it. Document what you do find and how you could fix it, present it to management.
 
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Ironically, in the UK, mechanical (pipework mainly) are still using imperial.
Rulers come with both metric & imperial, and many still use imperial measures i.e. most people set their car fuel consumption readings in miles per gallon (no not the US gallon).
So even though we went metric in the early 70's still used today.
 
When put in a position to do something less than safe. I always ask for thier lawyer to have a release from all liabilities drafted and signed by the controllers of the company. Then I will have my lawyers review for changes and corrections. This has always stopped them 100% of the time.

I usually just ask them what is a thumb, index or other fingers worth? Then I ask what is your child or grandchild's hand worth. " With the training that you provide for your employees do you feel safe putting your family running the machine" again we've never had an issue after that statement.

I will be able to sleep at night knowing I didn't help in getting someone hurt or worse.
 
I turned a project down due to the machine not being safe. I told them they also need to get that up to speed as well, and explained everything they need to do. They didn't have the cash...
 
I think you missed the point though. Its not always a deadly concern, sometimes it's just an injury concern because a machine used to meet regulation but doesn't anymore. If everybody flat out refused to work on a machine until the safety was upgraded.... there would be no business anymore, it's just not feasable so there has to be a middle ground, which I thought was with the company who owns the machine who is responsible for the safety of their employees. They must follow OSHA standards and are ultimately responsible for ensuring a machine meets the safety standards they came up with, which have to be at least the bare minimum for whatever process it is.

I missed responding to this, FWIW: This isn't a case of an old machine that isn't up to current code (or grandfathered out). This is a case of a machine that was built in-house by people who didn't know better in the last 5 years or so and this machine was NEVER up to codes and standards. It should have NEVER been designed or turned on in the first place.
 
I missed responding to this, FWIW: This isn't a case of an old machine that isn't up to current code (or grandfathered out). This is a case of a machine that was built in-house by people who didn't know better in the last 5 years or so and this machine was NEVER up to codes and standards. It should have NEVER been designed or turned on in the first place.

I think that still falls under my point though. How many contractors that help companies get their old machines back up refuse to work with them until they get original build files, original prints, original Built-As drawings, safety certifications, etc.

In my opinion, it's just impossible to come out somewhere for a quick 2-3 hour service call to troubleshoot an automation problem, and guarantee that the machine meet or has ever met safety standards without charging a customer 10 hours just to evaluate if you want to put your hands on it for the sake of CYOA legally.
 
…….and people wonder why USA-made products cost more. We all want workers to be safe and to require machinery to be built in a safe manner but this thread exposes why it’s so expensive. Insane legal requirements are a huge reason for this.

Same thing with doctors trying to treat patients and their fear of malpractice.

I sure am glad to be retired.
 
Guess if you are work for the company or being hired in to work on the machine.

Write a Tech report on the deficiencies and get a 2nd Engineers opinion. If its that bad walk way, but explain why you are refusing to work on the machine.

We had this and we advised our client we would not support the machine but offered to re-write /rebuild the machine then upgrade to include the new features but we would need to start from scratch and fix all the issues and it would cost $$$.
 
I'd say the general rule is unless there are positive measures to ensure your change(s) do not affect the safety of a process, don't modify it without getting safety expertise involved. Trusting the original programmer correctly segmented safety code and non-safety code isn't wise and it is not against standards to program safety-related logic in non-safety tasks (though if there exists a safety task, it should be used).

It's frustrating, because safety engineering is very expensive, but this just highlights why it is important to do this work on the front end. Whenever you take receipt of a dangerous machine or process demand a copy of the risk assess and a verification/validation document. The OEM is entitled to deliver the product without these documents but you are also entitled to refuse your business without them.
 
A pint's a pound, the world around!
Not sure which world you've been living in, but I've seen pints at 9.5 pounds already... :p
I missed responding to this, FWIW: This isn't a case of an old machine that isn't up to current code (or grandfathered out). This is a case of a machine that was built in-house by people who didn't know better in the last 5 years or so and this machine was NEVER up to codes and standards. It should have NEVER been designed or turned on in the first place.

I've seen flammable pressurised tanks built on site before... although to be fair, way back in the day manufacturing was very different when it came to machinery and systems as well as the skills available on a typical site. The site that built that flammable storage tank (which by the way passed inspection to current standards) had a whole engineering design team that designed an awful lot of stuff to a very good standard. Then bean counters took charge and everything became outsourced.
 
I was in a situation where a manager wanted me to replace a failed SSR without shutting the machine down (480 volts) I refused. He called another tech and asked him to do it, he also refused. Ultimately he had no choice but to shut it down.


Needless to say, I started looking for a different job after that incident and left a few months later.


Mike
That is why work orders should always be used without exception. No work order, no work.
This way, when a work order is submitted and maintenance, E&I, etc, start the work, the first thing is to turn it off and lock it out. Once the repair starts, maintenance owns the machine until the repair is finished and the equipment is put back in service and handed back over to production. This way, it doesn't make a rat's a$$ what the manager wants. It's out of his hands.

If you can't tell already, I have fought this battle before.
 
That is why work orders should always be used without exception. No work order, no work.
This way, when a work order is submitted and maintenance, E&I, etc, start the work, the first thing is to turn it off and lock it out. Once the repair starts, maintenance owns the machine until the repair is finished and the equipment is put back in service and handed back over to production. This way, it doesn't make a rat's a$$ what the manager wants. It's out of his hands.

If you can't tell already, I have fought this battle before.
Unless maintenance were the original "builders" of the Machine.

But I agree LOCK out and REBUILD.
 

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