ElectricalHammer
Member
Scenario:
1. An employer has a machine that isn't up to code/standards: hydrogen gas torch systems without safety shutoff valves, industrial robot with its gate and e-stop channels being run by non-safety PLC outputs, E-stops wired as single-channel PLC inputs, Gate switches wired as single-channel PLC inputs, HMI has an 'Emergency Stop' Button, a 'bypass button' exists to circumvent the gate switch allowing people to enter the machine while its running, no safety switching devices exist in the control cabinet (not even relays).
2. Employer asks you to make changes to the PLC program for process reasons.
IME, the advice I've always gotten from previous managers is that 'once you touch it, you own it', so you don't modify a PLC program or make changes to a machine that you KNOW isn't safe. Arguably, the engineer should perform a risk assessment and lock the machine out until it can be completely revamped and considered 'safe'. Or (gray area, I know), we can leave the machine run while plans are made to fix its problems while maintaining some plausible deniability... but the line that is not crossed is to make any changes to that machine, especially in the program, because then if anything bad were to happen, "who was the last engineer to make changes to the program?" means fingers get pointed at that person. My attitude is if push comes to shove and I am told/forced to make changes to a machine that I know is unsafe, then I turn it off until I fix EVERYTHING, including the outstanding safety issues.
So what's your guys take on this? Is the whole 'he who was last to change it owns it' standard sounding right to you? Is leaving the machine running already too much of a professional ethical problem? What's the response you would give to the employer? Are there any legal/regulatory/code resources that address this situation specifically?
1. An employer has a machine that isn't up to code/standards: hydrogen gas torch systems without safety shutoff valves, industrial robot with its gate and e-stop channels being run by non-safety PLC outputs, E-stops wired as single-channel PLC inputs, Gate switches wired as single-channel PLC inputs, HMI has an 'Emergency Stop' Button, a 'bypass button' exists to circumvent the gate switch allowing people to enter the machine while its running, no safety switching devices exist in the control cabinet (not even relays).
2. Employer asks you to make changes to the PLC program for process reasons.
IME, the advice I've always gotten from previous managers is that 'once you touch it, you own it', so you don't modify a PLC program or make changes to a machine that you KNOW isn't safe. Arguably, the engineer should perform a risk assessment and lock the machine out until it can be completely revamped and considered 'safe'. Or (gray area, I know), we can leave the machine run while plans are made to fix its problems while maintaining some plausible deniability... but the line that is not crossed is to make any changes to that machine, especially in the program, because then if anything bad were to happen, "who was the last engineer to make changes to the program?" means fingers get pointed at that person. My attitude is if push comes to shove and I am told/forced to make changes to a machine that I know is unsafe, then I turn it off until I fix EVERYTHING, including the outstanding safety issues.
So what's your guys take on this? Is the whole 'he who was last to change it owns it' standard sounding right to you? Is leaving the machine running already too much of a professional ethical problem? What's the response you would give to the employer? Are there any legal/regulatory/code resources that address this situation specifically?
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