Maintenance Safety

[Smoke]

I want to ask all a question. When we program a machine we make sure all interlocks are good (the machine is safe to operate). Do you any of you consider when maintenance is working on the machine in a less than safe condition? They may have a door off with a key in the safety switch, or the machine partly disassemble in an attempt to do manual motions to view the problem they are having. Have you done or seen the wrong HMI button pushed and the result or the motion isn't as expected.? Have you considered redundant manual motion buttons or a pop-up to ask if that is the motion that is truly wanted (on potentially harmful motion) knowing that the machine is safe with all guards, light curtain and tooling etc. Doing this to make maintenance think of what they moving before it moves. I would like to here your responses and the things you are doing. Thanks

[Ron_Smith]

I'm pretty stingy with manual machine functions. I would rather be called out to a machine and force something or provide a temporary jog function then take a chance of someone getting hurt. Side note: We're a manufacturing plant and all of our machinery is stand alone. So no single piece of machinery being down for a couple of hours dramatically affects production.

[Groo]

Firstly when any item of plant is opened the driving power should be off. Any manual override should not be allowed on HMI's, it should be local hard-wired push buttons, usually two that have to be pushed at the same time, ensuring hands are out of the machine. Safety relays such as Pilz etc are a must. Saying all that I have no idea what type of machine you are talking about.