I love finding homemade controls like the one above. Folks identified a problem and then used what they had to fix it. This one seems pretty well-constructed (compared to some I have seen). I imagine folks had to access the electrical panel, reaching over for some amount of time to troubleshoot and test things. This would have been quite a reach up and over, and might have tempted people to rest their feet on the pipes below (which may be minimally sensitive, but certainly are not load-bearing pipes).
A lesser worksite would have posted a sign saying ‘do not step on pipes!’ This one worked with people’s natural inclinations: get closer to the work (which is also the ergonomically healthy thing to do.)
I saw this at the heating plant and it reminded of a few others I have seen – maybe I’ll post them too. Perhaps I should start an e-textbook for students. 🙂